In norwegian we just say kjæreste, which translates directly to "most beloved". Entirely gender- and age neutral. It's pretty sweet.
I think "dearest" is a more direct translation, which is funny considering the word's old-people association in English.
What kind of boat is it?
Small cabin cruiser. Well, I said it's my boat but it's sort of my dad's. Actually mostly my dad's. That being the case gave him the privilege of naming it, hence it is christened "my wife's capitulation". He's kind of a troll sometimes.