Diver delights in tiny sidescan
Adventure diver Ben Burville recently trialled Tritech’ s StarFish sidescan sonar off the UK’ s North East coast. Testing its performance, he scanned the seabed at the wreck site of the cargo ship SS Somali, which sank under German fire in 1941 off Blyth.
StarFish is claimed to currently be the smallest sidescan tow fish on the market, measuring less than 15 inches. It has a unique shape that is optimally designed to move through the water whilst maintaining stability and consequently improving the quality of the seabed images.
Ben Burville said, ‘The kit is remarkably small! The StarFish sidescan sonar comes in a peli case and can be carried in one hand. I’ve used sidescan sonar in the past and the tow fish was more like a huge naval torpedo that needed two people to launch it.’
Starfish is easily powered from almost any source and comes with simple StarFish Scanline software. The user can simply plug it into a PC or laptop and play.
‘The fish itself is about a foot long and remarkably, the power cable and feedback cable doubles as the towing cable, added Burville. ‘One end is attached to the fish and the other to the gizmo software box with a simple connection. The only other thing needed is a laptop computer. It’s very easy to set up and is scanning the seabed as soon as you lower the fish into the water over the back of the boat.
‘The images provided detail 50m either side of the boat at a depth of 25m to 30m. Metal shows up white (as it reflects the sonar waves) and different densities give different shades of colour; objects proud of the seabed leave a shadow. Images are divided into port and starboard as it moves forward. I used the StarFish over the SS Somali where it helped pin point the location of the ship’s solid brass fire extinguishers.
‘In summary, there are many undiscovered wrecks out there and this impressive bit of kit puts the latest sidescan sonar technology into the budget of many dive clubs.’
StarFish can be used in several applications, including shipwreck hunting, dive clubs, underwater research, law enforcement, fisheries, offshore oil & gas and underwater engineering projects.
