Electrical, electronic, acoustic and sound apparatus and instruments, namely, sonar, all for use in subterranean, marine or underwater environments; signalling, measuring, counting, recording, surveying, tracking and monitoring devices, apparatus and instruments, namely, sonar; computerised sonar apparatus and instruments for marine geological surveys, all comprising sub-bottom profilers, transmitters, receivers, amplifiers, swell filters, power supplies, and catamaran-shaped flotation contai...