Special to PSDiver
Product Review
Shark Marine Navigator
March 2007
By Dominique Evans-Bye
Research and Development Officer
Ventura County Sheriff’s SAR Dive Team

The Navigator is a hand-held underwater imaging tool with strong applications for search and recovery diving. This review focuses on some of the features and benefits of the accessories available for the Navigator, applications for the unit and thoughts from first-time users.
PSDiver Life Guards
Los Angeles City Lifeguards team up with a Ventura County Sheriff’s diver for a Shark Marine Navigator demo.
Some particularly notable features are that the Windows XP-based unit is easy to operate while wearing gloves and during low visibility conditions. The 5-inch LCD screen provides enough illumination to make a dive light unnecessary. The device is easily portable with a dry weight of 15 pounds, and is neutral in the water.

Jim and Wendy Garrington from Shark Marine brought the Navigator to Lake Piru in sunny Southern California for the Ventura County Sheriff’s Dive Team and the Los Angeles City Lifeguards to evaluate. On this particular day, however, Southern California failed to uphold its reputation of never ending fun in the sun, as the air temperature on the docks read 40 degrees and the piercing icy winds howled throughout the day bringing the chill factor down to what felt to be about 20 degrees. Only one diver from the Ventura team was “man” enough to demo the unit in the lake along with the three LA City guards. Prior to arrival, Jim Garrington had downloaded a map of Lake Piru off Goggle Earth from the internet. With the Windows XP operating system, it was as easy to use the Navigator to zoom in on the search area, as it is to use a normal laptop PC. This feature integrates with the imaging and positioning accessories to allow for more complete and accurate documentation of the search area. It can be especially effective when adding sonar and satellite imagery into GIS.

Accessories/Options
All accessory ports are “wet” plugs. Accessories can easily be swapped in the field with no fear of water-damage to the electronics. Shark Marine Technologies took care to make this system as diver-friendly as possible.

Applications

Public safety diving is inherently dangerous. Anytime technology can be used to lessen the risk to divers, it should be given serious consideration. The Navigator has the potential to significantly lessen search time for divers.

The Navigator can be equipped with either a 450-foot range or a 180-foot range high resolution BlueView imaging sonar. The range can be adjusted and fine-tuned underwater by the diver as needed just by a turn of a knob. The imaging sonar simply shows what is out there in the area to be searched no matter what the visibility happens to be. Images are clear and easy to interpret. The diver only has to scan the area, then use the navigator to find his/her way to the object to begin documentation/recovery procedures.

WAAS GPS surface positioning can be recorded by the Navigator Dive Log software allowing the search path to be geo-referenced into a downloaded map of the area. The GPS is plugged into one of the many “wet” ports for accessories. When diving at shallow depths, the Navigator can be equipped with a water-proofed GPS that floats on the surface and is towed with the unit by a cable. This method has been successfully used by the California Department of Fish and Game to geoposition an ROV in order to survey marine life in the kelp forests off Fort Bragg. (Veisze, Karpov 2002) Realizing that for many teams, a loose fin strap or extra cutting device can create major fears of entanglement, there is another method that can be used for plotting the search path. A diver can keep the GPS contained on a line management system, and release the cabled device to the surface to record a position reading at pre-designated intervals (i.e. number of fin kicks, or time intervals.) It is a tedious, yet effective technique.

With a variety of mounting options, the user has flexibility in deciding how the search would best be conducted. Pole mount allows topside to do a search from boat or dock. Hull mounted units can use a boat to run search patterns for wide areas, DPV mounted Navigator units would leave even James Bond envious. “Q” has nothing over Shark Marine.

They have also made it so the unit can be quickly disconnected from the DPV underwater and used by hand when necessary.

Hull searches can be conducted with use of the 90- degree mount with either imaging sonar or scanning sonar. Target identification can be done at safe distances and with a low magnetic signature version as an option.

The Navigator can be effectively operated by first-time users after a short shore briefing. In order for users to maximize proficiency in the least amount of time, Shark Marine offers a training program covering: The participants in the Lake Piru demonstration enjoyed getting out of the cold wind and into the lake to try out the Navigator. All agreed that the Navigator could increase diver safety for recovery operations. Los Angeles City Lifeguard Trainer Dan Guevara stated, If we could get this, it would really reduce dive time and manpower with proper training.
PSDiver Lake Piru
Los Angeles City Lifeguards (from left to right) Marco Rodriguez, Ruben Carmona and Trainer Dan Guevara with the Navigator at Lake Piru.
LA City Cabrillo Beach guard Ruben Carmona added that it would be an aid in avoiding underwater hazards and identify topography changes due to dredging. Carmona was impressed with the unit, declaring it to be lightweight, easy to move, practical in design, just point and shoot.

Guard Marco Rodriguez also was impressed by the Navigator, It was great. What you can do with it is amazing. It can really shorten your period of the search. He made the analogy that it was like night vision underwater.
PSDiver Dive Trainer
Dive Trainer Dan Guevara enters the water easily with the lightweight, highly manageable Navigator
The Navigator is another tool for today’s public safety dive teams. It has the versatility to be used as a diver-held system, mounted to a platform such as a boat hull, or parted out for the accessories to be used on a pole mount for a topside survey of the search area. For more information on the Shark Marine Technologies, Navigator, visit their website www.sharkmarine.com.