I think Water-Hover sounds a little strange and isn't exactly clear for the Piranha/Mend/Fabbers, it also isn't very distinct from just 'water' naval units. I would recommend Shallows naval units and Deep-sea naval units for a more clear and distinct separation.
I agree with this! The name water-hover sounds like the units just hover on top of the water. which I know some people will put 2 and 2 together and say "oh that means they can go over shallows" but a lot of people will not put 2 and 2 together so to accommodate them I agree that shallow naval and deep sea naval be in the names or something of the sort.
Water Hover can go into deep water. Water Hover is impervious to torpedoes. Using Shallows can imply the opposite.
Hover is impervious to torpedoes How is this obvious to anyone who hasn't played PA for awhile already? ---- Alternative question: Can Water Hover go on land or lava?