A Frame: An A frame is a stern mounted launch and recovery system on a ship designed to pick up and deploy large, heavy oceanographic equipment. A frames are typically very tall so that they can reach well behind the ship and close to the water when releasing or retrieving a submersible or ROV. The sides of the A frame are typically as wide as the ship and narrows at the apex, resembling the letter A.

Acoustic Release: An acoustic release is a mechanism that can be triggered by sending a specific sound frequency through the water. When triggered, the mechanism unlatches and the item that was on bottom is released to float to the surface. These devices are commonly used on sensor/instrument packages that a submersible will position on bottom and a ship will later pick up at the surface.

ABS: American Bureau of Shipping. -One of the most well known “classing” agencies for submersibles, but most widely known for their certification/inspection of ships. ABS is based in Houston, Texas. www.eagle.org

ADCP: Acoustic Doppler Current Profiler. An ADCP is an instrument used to ascertain water currents and their velocities in the water column. Even when the surface seems quiet, mid water or bottom currents can move like underwater rivers, causing sudden and challenging situations for submersible and ROV pilots. ADCP helps to locate these currents before they are encountered and helps the diving supervisor to determine if conditions below are safe for submersible operations. http://en.wikipedia.org/wiki/Acoustic_Doppler_Current_Profiler

Aft: The rear most part of the submarine, also called the stern

AAV: Autonomous Ariel Vehicle. An AAV is launched from the shore or from the deck of a ship and is used to gather atmospheric and video data. These systems have been used by the US Coast Guard to monitor whales, polar bears, seals and other marine mammals in the Arctic. They are also being used for fisheries enforcement in marine protected areas, especially in the large marine monuments near Hawaii and Northern Marianas Islands. These vehicles launch via a catapult and are recovered with a catch wire.

Alvin: Alvin is a 4500m research submersible owned by the US Navy and operated by Woods Hole Oceanographic Institute. It is one of the most well know research submersibles and is named after legendary oceanographer, Al Vine. Alvin works from the dedicated submersible tender, R/V Atlantis.

Archimedes’ principle: Any object, wholly or partly immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. http://en.wikipedia.org/wiki/Archimedes%27_Principle

AUV: Autonomous Underwater Vehicle. An AUV is un tethered and runs on batteries. They are used primarily for survey/mapping tasks using on board sonar. Some AUVs are equipped with cameras and environmental sensing equipment. They range in size from small two person deployable systems up to large long range systems requiring special launch and recovery systems. Also known as a UAV, underwater autonomous vehicle or UUV unmanned underwater vehicle. An AUV can act as a scout, mapping terrain for the submersibles to explore in detail.

Ballast: Submarines employ ballast to alter the vehicles buoyancy. This allows it to submerge or ascend in the water or can be used to just trim the crafts balance or attitude. There are several types of ballast systems in a submarine, hard ballast, soft ballast, and variable ballast. Typically ballast is varied by taking in water inside a tank to decrease the vessels buoyancy for diving, and blowing the water out with air to add buoyancy for ascent. Trim ballast is a weight that can be moved back and forth from fore to aft to adjust attitude.

Bathyscaphe: Comes from the Greek words Bathys (deep) and skaphos (ship). This is a type of submersible with the personnel sphere suspended below the flotation. The most famous bathyscaphe is the Trieste – a vehicle built by the famous inventor August Piccard whose son Jacques along with Lt. Don Walsh set the record for the deepest dive to the bottom of the Challenger Deep in 1960.

Beam: The beam of a ship is the width at its widest point.

Bio-prospecting: Bio-prospecting is a growing field of studying marine life for potential medical/pharmaceutical applications. Deep water sponges, corals, and bacteria are common targets for this research.

Breezy: Generic term for high wind conditions that are unfavorable for submersible operations or almost any other over the side operations.

Bottom Trawling: Bottom trawling is a destructive fishing method by which large heavy plates/blades are dragged across the sea floor, depositing entire marine life habitats into a net. The mixed catch is sorted at the surface with only target/commercial species being retained. Submersible pilots, observers, and ROV pilots have likened the resulting damage to using a bulldozer to pick apples.

Bow: Front part of submarine

Brow: The front overhang over the personnel sphere of some submarines is referred to as the brow.

Buoyancy: is the weight of the vehicle, W_v divided by the weight of water W_H20 it displaces.

Cavitations: Cavitations are the formation of bubbles in water when something such as a propeller moves rapidly through it and creates a low pressure zone which is lower than the vapor pressure. As the bubbles collapse a resulting noise signature is created.

Class: A human occupied submersible should be “classed” by one of the several classing agencies that oversee and approve designs for testing and safety aspects and review the work from design through build. Classed submersibles must undergo annual and periodic major inspection ensuring a high degree of safety. Lloyd’s and ABS are the two most familiar classing agencies for manned submersibles.

Certified Materials: When building a submersible to class, all raw materials must be certified, meaning that there must be 100% traceability and chain of custody from the original source through every vendor/process and ultimately to the submersible builder.

Challenger Deep: See Mariana Trench

Collision Avoidance Sonar: This type of sonar is used to scan ahead of where an underwater vehicle pilot can see to alert for potential hazards ahead. It is roughly equivalent to “instrument flight” in an airplane and helps the submersible or ROV pilot to see ahead, even in murky, dark, or turbid water. -Also known as forward scanning sonar.

Convergence Zone: A convergence zone is a region in the water where two different currents or layers of water (often with different temperatures and densities) meet. These regions are often highly biologically active.

CTD: A CTD is an essential oceanographic tool used to measure Conductivity, Temperature and Depth of sea water. The instrument has a number of “bottles” that can be selectively closed to collect isolated water samples at different depths. CTD’s that are deployed from a ship can provide real time information to the surface while remote CTD’s on a submersible or AUV have on board recording and are not as large. http://www.whoi.edu/instruments/viewInstrument.do?id=1003

Cutter: Any of the large ocean going ships operated by the US Coast Guard and the most welcome sight in the world to a ship in distress. http://www.uscg.mil/

Decompression: The time period that is required for a diver’s body to rid itself of excess nitrogen that can build up in body tissue when breathing compressed air at depths below 30 ft. One atmosphere submersibles do not require any decompression as internal pressure is the same as that at the surface.

Deepflight: This was a full ocean depth concept by Graham Hawkes and Sylvia Earle. An experimental prototype was built by Hawkes but the development program was not funded.

Deep Rover: The original Deep Rover was a one person submersible capable of diving to 1000m/3300 ft. It was retired in 2004 after 20 years of service. A pair of two person Deep Rovers were built in the early 1990’s for Canal Plus, a French television firm. Later acquired by James Cameron, they were used as film/lighting platforms during the making of Titanic.

DeepSee: A shallow water three person tour/research submersible built by SEAmagine which operates at Cocos Island.

Deepsearch: Deepsearch is a full ocean depth submersible currently under design and development. It is intended to be a world asset, providing working access for scientists to all areas of the sea.

Deep Worker: Deep Worker is a small, one person submersible designed by Phil Nuytten, built around the premise of a business class airline seat. It is a widely accepted design and DOER trained more than 100 people to pilot these submersibles during the 5 year Sustainable Seas Expeditions. A two person version called Deep Worker Dual has met with more limited success.

Displacement: As an object that sinks, it displaces an amount of fluid equal to the object’s volume.

Diving Bell: In its most simple form a diving bell can be visualized as an inverted metal bell shaped housing that traps air inside if it is lowered straight down into the water. Divers can then swim up into the bell to get air. However, modern diving bells are complex life support systems that allow commercial divers to remain underwater for days or weeks at a time. When the bell is recovered, it connects to a decompression chamber where the divers are slowly acclimated to surface pressure before emerging.

Diving Plane: The diving plane is a control surface used to help steer the submarine. Usually these are paired flaps (one on each side of the submarine) that can rotate to help angle the submarine up or down. Fairwater diving planes are positioned mid ship, typically on the conning tower, are used to help raise or lower a moving submarine without pitching the vehicle.

Diving Profile: The diving profile is the path the submersible takes from the surface to the working depth and back. Most deep water submersibles have a profile of becoming heavy and sinking to the working depth, dropping some weight to become “neutral” or stop sinking. Work is then conducted until more weight is dropped and the submersible floats back to the surface. Also see static diving and dynamic diving

Diving Supervisor: The diving supervisor oversees all aspects of the submersible diving operations. He/She conducts or reviews pre and post dive check lists, physically inspects the submersible, checks status of certification and is in constant communication with the submersible during a dive. The diving supervisor works closely with the ship’s captain and boson during launch and recovery and has final decision making authority in submersible operations.

Down Bubble: An inclinometer used to measure the angle of descent of the vessel.

DP: DP stands for Dynamic Positioning and refers to the ship board equipment that allows the ship to maneuver with very precise positioning and control. With DP II or DPIII a ship can maintain a very precise position, even in rough seas. DPII is considered standard equipment for a ship engaged in over the side operations.

Dry Lab: A dry lab or main lab is the area aboard ship where specimens, samples, and data may be handled or analyzed. It is also where most electronic equipment such as underwater cameras, lights, or other housed electronics can be serviced/repaired.

Dynamic Diving: During a dynamic dive, a submersible uses its control fins to guide itself downward while under power. Deepsearch incorporates dynamic diving in its dive profile.

Exo-structure / Frame work: This is the part of the vessel that holds the internal components and sometimes incorporates ballast tanks.

Fairing / Skin: The outside layer or covering of the vessel – mostly useful for streamlining the flow underwater and avoiding entanglement on objects such as derelict fishing gear.

Fathom: Six feet or 1.829 meters

Fish: U.S. submariner’s nickname for a torpedo. -Also, a common term for “side scan” sonar units, which are towed behind a ship on a cable.

FLIR: Forward looking infrared radar. This type of camera can help with navigation through fog or at night.

Forward Trim: Variable ballast tank used to adjust the submarine’s weight and tilting movement.

Front Porch: The front porch is the area on an ROV or submersible where samples and/or sampling equipment may be carried. Additional cameras and/or lights can be mounted here as well. It is a flexible, open and configurable space.

Ghost Net: A ghost net is a large commercial fishing net that has been lost or abandoned at sea. Such nets catch and kill a wide variety of sea life before becoming heavy with carcasses and sinking to the bottom. When the sea life decomposes, the net rises up again due to the floats it carries and the process starts again. The nets are light and strong and do not readily decompose so may continue killing for many years. They are a hazard to all underwater vehicles and may become entangled on shipwrecks, killing fish that are attracted to them and presenting a hazard to divers.

Gertrude Telephone: Older term used to describe many types of underwater communications equipment.

Glassy: Flat calm water, generally perfect for diving submersibles.

Gradient: A layer, where the temperature of the sea water, and to a lesser degree its density, changes abruptly, thus sending sound waves of echo-ranging clear of a submarine below the layer.

Habitat: A habitat is an underwater laboratory where scientists can remain for up to two weeks at a time before decompressing and returning to the surface. Sea Lab, Tektite, and Hydro-lab are examples. Today, the Aquarius habitat in Florida is the only such laboratory in the world.

Harmony 7000: The Harmony 7000 is a research submersible currently under build by the People’s Republic of China and is projected to dive to 7000m. If successful, it will become the deepest diving submersible in operation. While very little is known about the Harmony 7000, it is believed to be designed for minerals/resource exploration.

Heel: to list over to one side.

Housing: Housing are enclosures that can be either oil filled or dry/1 atmosphere and hold electronics and/or sensors that must not be in direct contact with sea water.

Kaiko: Kaiko was a robotic vehicle designed and operated by JAMSTEC to reach full ocean depth. In 1996 Kaiko made a dive to the Marianas Trench and retrieved live bacteria. In 2003, the vehicle was lost during a typhoon.

Knots: This is the nautical unit of velocity equal to 1 nautical mile per hour, about 1.15 miles per hour or 1.85 kilometers per hour. While the Knot does not fit within the SI system of measurement, it handily is almost equal to one minute of latitude which makes it convenient for navigation and is therefore still used.

LF signal: Low Frequency Signal

Lloyd’s: Lloyds is a well known and respected classing agency for ships and submersibles. The Lloyds Registry is based in Aberdeen Scotland. www.lr.org

Lock out: An air lock system of hatches that allows divers to enter and leave a submarine while underwater.

Lumpy: Sea state which is unfavorable for launch and recovery of submersibles

Mariana Trench: The deepest part of the world’s oceans. Located in the western Pacific Ocean near the Mariana Islands, it is also known as the Marianas Trench. http://en.wikipedia.org/wiki/Mariana_Trench

Marine Debris: This generally refers to lost or abandoned fishing equipment such as nets and traps but also includes any man made trash or debris in the ocean. Humpback whales have been known to get entangled in marine debris such as Alaskan crab traps and tow them all the way to Hawaii at a great physical toll to their bodies.

Marine Protected Area: Marine protected areas are regions that have been set aside for special environmental protection. While most people equate these areas to National Parks on the land, the difference is striking. While parks afford protection to the plants and animals that live there, marine protected areas, marine sanctuaries, and even marine monuments all allow fishing to some extent. Only “no take” zones offer real protection and most are so remote that enforcement is difficult.

MIR: MIR is the name of the two well known 6000m Russian research submersibles. They operate mainly from the submersible tender R/V Keldysh but have operated in Lake Baikal for two seasons. The MIR submersibles are most famous for their work on the film “Titanic” and they were also first to explore the Bismark and reach the underwater North Pole point.

Momsen Lung: A breathing apparatus to permit an individual to breathe normally while escaping from a sunken submarine; also serves as a gas mask in the submarine and as a life preserver on the surface. Named after Charles “Swede” Momsen, the innovative Navy diver who developed it. http://www.onr.navy.mil/focus/blowballast/momsen/default.htm

Moon Pool: -A thru hole in a ship large enough to accommodate launch and recovery of oceanographic equipment such as ROV’s and submersibles. Moon pools usually are covered by steel plates or retractable hatches when not in use. http://en.wikipedia.org/wiki/Moon_pool

MPA: See marine protected area

Multi-beam: Multi beam is a type of sonar that produces multiple acoustic beams in a fan shape across the ocean floor, providing a detailed acoustic image of the sea floor, roughly equal to an underwater topographic map. Multi-beam is usually mounted to the underside of a ship and takes images as the ship travels. Some underwater vehicles can carry multi beam as well.

Nautile: Nautile is the 6000m French research submersible operated by IFREMER.

Negative Buoyancy: A condition attained when the submarine weighs more than the water it displaces, thus causing it to submerge and sink.

Nemo submersible: A collective term for any submersible that incorporates a full acrylic ball for a personnel sphere. Examples include the two person Deep Rover (DR1002) and the Triumph submersible.

Nereus: Named after a Greek sea god, Nereus is an unmanned robot “hybrid” ROV, designed to use elements of an AUV, lithium batteries and a very thin fiber optic tether to reach the deepest part of the ocean. After years of development, Nereus touched bottom in the Marianas Trench in May of 2009. http://en.wikipedia.org/wiki/Nereus_(underwater_vehicle)

Neutral Buoyancy: A submarine can achieve neutral buoyancy when it’s dry weight is equal to its displacement (the weight of the water displaced by its volume). Usually the submarine pilot must use a variable ballast system to achieve this balance. A neutrally buoyant vessel can “hover” at one depth without sinking or rising.

NOAA: National Oceanic Atmospheric Administration. NOAA operates a number of US research vessels and is recognized for its public outreach/education efforts.

Noise signature: Most vessels have a unique noise signature – they can be identified just by the sound that they make. -Also known as acoustic signature.

Observers: The observers are the passengers aboard the submersible. The observers are generally making direct physical observation of the sea bed and/or operating the manipulators and light/camera systems. The observers typically are responsible for collecting and securing samples, recording video, and other scientific information. The pilot and the observers work as a team especially when the submersible is near delicate underwater features or potential hazards such as ship wrecks.

One Atmosphere: One atmosphere refers to the pressure found at the surface of the water. Each 33 feet of depth is considered an atmosphere. Thus a depth of 37000 feet in the ocean is equal to 1091.423 atmospheres or 16039.5 pounds per square inch versus the 14.3055 pounds per square inch at the surface.

Over the side operations: Over the side operations refer to any work done on a ship that involves the launch and recovery of equipment such as AUV, ROV, or submersibles.

Package: A stand alone battery powered unit containing oceanographic sensors and/or cameras to remotely gather information from the sea bed. A package may be placed on the sea bed by a submersible or ROV and left behind. The package can be collected later or designed to automatically return to the surface via a physical or acoustic release mechanism.

P.B.O.F: Stands for Pressure balanced, Oil filled and is used in reference to a type of enclosure that has been filled with oil and allowed to see the ambient pressure at depth. Since the oil is incompressible and a good electrical insulator it’s commonly used to protect instrument and electronics boxes from the high underwater pressures, without having to make expensive and heavy water tight chambers to withstand these high pressures.

Personnel sphere: This is an internal hull with heavy walls to withstand the forces of the water pressure at depth. Usually this is a spherical or cylindrical shaped chamber where the pilots and other crew are contained at one atmosphere of pressure. Traditional materials include steel and titanium for deep ocean submersibles and acrylic for depths to 1000m. Promising new research is investigating advanced ceramics and even glass, one of the oldest, strongest, yet most mysterious materials known to man.

Pilot: The submersible pilot is the person controlling the movements of the submersible while in the water. He/She must be proficient is all aspects of navigation, sonar operation, life support systems, and monitoring all power and control systems during the course of a dive. The pilot communicates with the diving supervisor, reporting systems status every 15 minutes. The pilot is responsible for the safety of the passengers and implementing emergency procedures if necessary.

Pitch: The angle or tilt of the sub aft to fore.

Port: Left side of submarine

Positive Buoyancy: Condition a submarine is in when its submerged displacement weighs less then than water it displaces. When a submarine is positively buoyant, it will rise to the surface.

Pressure Hull: The submarines inner hull and conning tower; built to withstand the sea pressure at a stipulated test depth plus a generous safety factor.

Pressure Pot: -A chamber that can be pressurized to simulate the forces of the deep sea pressure on objects in a controlled, test environment. Such chambers can be used for proof of concept or materials testing, to certify parts and components, or to conduct periodic “over pressure” testing of personnel spheres as an additional measure of safety.

Re-breather: Closed system breathing apparatus that divers can use instead of SCUBA. Re-breathers are exactly that, exhaled air is “scrubbed” of carbon dioxide and the diver breathes it again. Small amounts of oxygen are added as the body consumes it. The advantage of a rebreather is that there are no bubbles or loud noises making it easier to approach underwater wildlife and to film underwater without curtains of bubbles in the picture.

RHIB: Rigid hull inflatable boat. These sturdy small craft are used to work around the submersible when it is in the water and to deliver the swimmer to and from the area during launch and recovery.

ROV: Remotely Operated Vehicle. ROV’s are perhaps the most versatile of underwater tools. They come in a wide variety of sizes from the tiny palm size “video ray” to massive bus size behemoths that serve the offshore oil industry. These vehicles are all controlled from the surface by way of a tether or umbilical cable. They provide real time video back to the surface. ROV’s that support submersible operations are always large, hydraulic machines that are fitted with multiple cameras and manipulators to render aid in the event of entanglement or loss of power. These “Swiss army knives” of the sea can be fitted with a wide variety of tools and sensors. DOER Hydraulic ROVs

SAS: Synthetic Aperture Sonar. This type of sonar is capable of providing very high resolution acoustic images of the ocean floor. The closer the unit is to the sea floor, the better the image. These devices are most often used on AUV systems.

SCUBA: Acronym for Self Contained Underwater Breathing Apparatus but today recognized a word on its own. Collectively refers to the sport of scuba diving which is regulated by agencies such as NAUI and PADI worldwide.

Scrubber: The scrubber is the mechanism that is used to remove excess carbon dioxide from re-breather air or the air inside of a submersible. Most submersibles have at least two scrubbers for redundancy and safety.

Shinkai 6500: The Shinkai 6500 is the deepest diving research submersible today. It is operated by JAMSTEC the Japanese marine science and technology center.

Shot: Unit of measure, generally in reference to anchor chain. 1 shot = 15 fathoms or about 90 feet.

Sled: A sled is any kind of instrument package that is towed behind a ship. Most often this term references a camera sled which can be towed above the sea bed in clear water to look for lost objects such as shipwrecks. It can also be used by scientists to look for deep water reefs or other interesting habitats.

SMR: Science Mission Requirements. The “SMR’s” were developed by and are periodically updated by UNOLS collaborators. They outline the basic suite of equipment that a research vessel should carry along with recommendation on each class of research vessel including coastal, fisheries, and oceanic.

Soda Lime: is a chemical, usually a granular material, which reacts and bonds with CO₂ and is commonly used inside submarines and re-breathers to remove or scrub the CO2 from the breathing air. Brands such as Soda-sorb and Sofno-lime are widely used.

Sonar: Sonar is the underwater equivalent of radar. It allows one to see through the water using acoustics. Forward looking, collision avoidance, dual frequency, multi-beam, side scan, scanning, and SAS are all different kinds of sonar, each providing an electronic acoustic image of what the unit “sees”.

Starboard: Right side of submarine

Static Diving: Static diving refers to diving through decreasing a vehicle’s buoyancy – typically by letting water into the ballast tanks, as opposed to using power/thrusters to dive.

Stern: Back part of submarine, also see “aft”

Submersible: A submersible is a one atmosphere underwater vehicle capable of carrying 1 to 3 people for research, observation, or commercial work.

Submarine: A submarine generally refers to the large underwater military craft. It is also the ubiquitous term for large computer or software projects that fail to succeed.

Submarine Tender: A submarine tender is a type of ship that is dedicated to the support of a submersible or submarines. An example is the R/V Seward Johnson.

Surface Layer: The water between the ocean top and the first thermal boundary – usually from 50 to 200 feet but depends on weather and surface conditions.

Swimmer: The swimmer is the person who removes tag lines, un-hooks the submersible from the ship, and gives a final visual check of the craft in the water before the sub dives.

Tag Line: Rope or line that is attached to the submersible or ROV during launch and recovery to help stabilize the vehicle during launch and recovery as it is picked from or landed onto the deck.

Tender: The tender is a small craft that is used to collect or deploy the swimmer during submersible operations. The same craft is usually used to support any SCUBA diving operations on the research ship.

Thruster: A thruster is a “bolt on” assembly which has a motor and propeller and is used to maneuver a submersible or ROV in the water column. An ROV may have many thrusters while a submersible may have a main propeller with thrusters used for more “close quarters” or sampling work.

Tour Sub: A tour sub is a submersible that is designed to carry 5 to 45 people for observation is shallow water. The most well known example is Atlantis, a tourist submersible operation based in Hawaii.

Trieste: Trieste was the first and only manned craft to reach full ocean depth in 1960. Captain Don Walsh and Jacques Piccard were aboard. No one has been back since. Trieste was weighted down and sank to bottom, then released weight and using an enormous fuel filled bladder for buoyancy, floated back to the surface.

Trim: The balancing of a submarine’s weight and equilibrium underwater.

U-boat worx: Builders of the C-Quester submersibles, 2 or 3 person craft for 100m operations.

Upwelling: Term for water that is moving up from the deep into shallower water carrying nutrient rich waters and attracting marine life. Sea birds, whales, and fish converge in these zones to feed on the sardines and anchovies which are attracted by plankton and krill. Upwelling zones are some of the most productive regions in the seas .http://en.wikipedia.org/wiki/Upwelling

UNOLS: University-National Ocean Laboratory System. -A group of 61 academic and National Laboratories who work to coordinate their oceanographic research missions and ships to mutual benefit. http://www.unols.org/

UWT: Underwater telephone. This is a NATO recognized device for communicating underwater.

Variable Ballast: Variable ballast is a system by which water is pumped in or out at a variable rate to adjust the position or payload capacity of an underwater vehicle. A variable system like this allows vehicles to pick up objects underwater or to place objects underwater without uncontrolled sinking or floating.

Wet Lab: A wet lab is the area on board a research ship where specimens first go once recovered from the submersible or ROV. Some wet labs have tanks for holding live specimens and others have equipment for preserving specimens with chemicals or in very cold temperature freezers.

Wet Sub: A wet sub is a submersible vehicle in which the pilot and observers wear SCUBA equipment and are exposed to the surrounding water rather than contained in a personnel sphere. Great care must be taken to avoid rapid changes in depth to avoid pressure related illness/injury such as embolism and the bends.

Z Drive: A Z drive is an azimuth thruster pod (s) mounted to the ship that can rotate 360 degrees providing very rapid changes in direction and positioning. They are very useful for ships involved in submersible operations as they can keep the ship positioned even when the main ship propellers are off. http://en.wikipedia.org/wiki/Z-drive