I hesitate to ask for what may well be the obvious answer, but did U-boats use nautical miles and knots for their navigation?

My question is primarily aimed at the situation in WW1 (presumably the same applied to the WW1 Kaiserliche Marine as well as the WW2 Kriegsmarine).

Just to define my question a little more, I am thinking of the the Imperial measures - 1 nautical mile being 6,080 feet and not the current International Nautical Mile of 1,852 metres. 1 knot being 1 nautical mile per hour (1.151 land miles per hour).

I guess depth was measured in metres.

Many thanks.