They seem a reputable experienced company who do not need to make extravagent claims.
Not extravagant? Maybe to put a suitable analogy here, their claims are equivalent to "We built a prototype airliner for 500 passengers that can travel at Mach 8, does not create any sonic boom and needs 100 kg of fuel for a transatlantic flight. We are not saying how we are doing it, but we have 23 or 47 people working it, 12 of which have a PhD and 5 of which are professors. The plane was built using secret Soviet military technology. We sent a presentation to both Boeing and Airbus and are very surprised not to have heard back from them. We are not saying that this is the aeroplane of the future. But they should at least follow up as a potential lead for future airline technology!". Why? It is for three reasons of physics, military technology and economics:
(1) No electromagnetic wave can travel through water very far before being absorbed. Only ELF waves with a frequency of less than 100 Hz used for communication with nuclear submarines can penetrate a few hundred metres. The transmitters and antennas used for these waves are huge, expensive and power hungry so that there are only two or them in the US and Russia. Nothing on a plane wreck sitting on the ground of the ocean can create such waves so no electromagnetic detector on a aeroplane or satellite can detect any electromagnetic waves originating from the wreck.
(2) This technology could be used to spot submarines. If such technology exists, why do the nuclear powers still build hunter-killer attack submarines that try to sniff out the location of the enemy nuclear ballistic missile submarines? And why bother having nuclear ballistic missile submarines, the threat of which relies on being stealthy, if they can simply be detected from space?
(3) This technology would instantly reveal all mineral and oil deposits of the whole world. Why do the oil and mining companies then rely on other expensive, unreliable, methods to find valuable resources?