- An actual term
The two also seem to be similar in usage; there are four questions using both of these tags and one uses both.
Should we combine the two? I'd suggest one as a synonym of the other but I lack the necessary in rep in either tag. I'd also like to hear a discussion on this.
Note: shipbuilding can apparently also be used for spaceships, so my preference would be to get rid of the water-vessel-design tag by making it a synonym of shipbuilding, and use shipbuilding instead.