I'll second Erolfa.. it's a great aquatic!
Also, give a sniff to Versace PH. It's a bit heavier than some aquatics - a bit woodier in the drydown and a bit more formal/elegant - but also has more depth than some, I feel. Excellent longevity on my skin!
This one doesn't have much development but it's very very fresh and utilizes mint (a tricky note) quite well - Hugo XY. It's aquatic in the sense that it smells like water.. frozen. Like a freezer full of ice. Very clear/transparent smelling. Longevity is good but not great. Still, it's something quite different than most of the aquatics.
Nautica Voyage is quite nice too and has a strong mimosa note in it. Very smooth.
Lastly, I really enjoyed Nautica Oceans. It smells a bit like Allure Homme Sport (lots of bittersweet lemon action), but is saltier and somehow smoother, to my nose, especially once the lavender in the heart kicks in. This perfume is different too in that it does not use alcohol as a solvent but instead uses only pure water - this gives it a much different feel on skin. It is really refreshing to spray on, and of course there is not even a moment of alcohol in the topnotes.