This looks great. Ships look good, ocean is nice, overall feel and particles everywhere.
Only critique: I'd completely distance yourself from the "MMO" stigma. Since you clearly state it's not in the description, and it's attached to project failure and nutjob hobbiests. It's false advertising.
personally i will pay a little more attention on particle systems in game , u know , now looks like u r get particle systems from illusion software. U kno what i mean? Looks to much 2d when i wach clip on utube (smoke & water splashes) also i believe fire need to be a little more transparent. But all of this what i we say is just a little bit of tweaking,nothing more ,i believe. Another thing what i believe will be nice thing to have is: fire give light, right? Check SeaCraftAlpha 2:06 , so i will add some light in fire specially for night battle. But u got a good wave
Boshko Savich, you're right, we will pay more attention to particles in future Today most of particles are "only for test".
The bottleneck of SeaCraft is ocean - it is hard part, which need a lot of attention to make it fast on low-end computers with good quality. It is not a problem to make a cool ocean for high-end hardware, but this way is bad for online games.