I concur! I think it'd be a great idea if the IJN ship names were romanised properly. In my opinion, I think the addition of 'u' in the word looks much nicer than the accent line above the singular vowel, but either would be better than the extremely westernised versions currently in-game.....
And I was sure Tenryuu was the nameship, not Tatsuta, glad I wasn't just going mental... XD