Trongle is a device used on submarines to help swimmers, especially the naval

special forces Special forces and special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equip ...

, to locate a submerged

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

in order that they may return to it. The trongle was invented by Captain John Moore of the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...

.Captain John Moore obituary

The Daily Telegraph ''The Daily Telegraph'', known online and elsewhere as ''The Telegraph'', is a national British daily broadsheet newspaper published in London by Telegraph Media Group and distributed across the United Kingdom and internationally. It was fo ...

24 August 2010.

References

Armed forces diving {{Navy-stub