It’s nice to see a mod idea turn into reality! 
I have no idea if this is possible, but putting an animated shader overlay that provides a wavy effect to the top surface of ships. I really like the idea of spires, since they can be relatively vertical for collision box purposes. One issue would be having pieces sink or float on death, but could have really cool muzzle and explosion effects https://www.youtube.com/watch?v=OubvTOHWTms
Amazing! A mod like this will be even better with that in it.
I hadn’t thought about having the pieces sink…I wonder if spawnsalvageondeath can be tweaked for it.
I don’t get what you mean by wavy effect? A screenspace distortion like what happens when you pull up the pause menu?
I haven’t messed with effects lately, but if I recall correctly there’s gravity stuff in there. Having stuff float up, like the wafting smoke of the stock damage effects, as well as falling down, should be possible. Making it look like it’s under water might be a bit tricky though.
Ohhhh! Caustics is the term I’m familiar with. Hmmm… Maybe something like projecting an animated texture onto surfaces that are visible from the pov of a camera facing downward from the top of the level.
Oh i am totally like wanting to give ideas now!!
hmmm…when your ships blow up under water…there needs to be like a giant bubble form around the ship as it blows up and then collapse as the explosion dissipates…kinda like the shock wave effect around the muzzle of a gun underwater
And maybe even an implosion. A “reversed explosion” quickly turning into an explosion after it collapses in the middle.
all the explosion based weaponry will need this effect 
Cavitation bubble effects are planned. 
Sounds good! This is so interesting I clicked the watch button at the bottom! 
Are you going to model the sea floor as well?
You could also make ships take damage if they reach a certain depth, and have this depth vary between ship types.
Nice added tactical depth!
And I swear, no pun intended.
An invisible radiation nebula?
And sorta planning to model the bottom - the initial plan is to steal Anno’s idea:
The bottom is sorta there, but it fades off to pitch black so that it looks like the actual bottom is way off down deep. That doesn’t preclude a map with a bottom and a kill zone though.
This mod is boss. The strides made already are brilliant. If I could make one suggestion, I would say consider merging this with the Classic Space mod. I don’t know how you would do that but it would be sweet to have epic Lego warfare in space and under water all bundled together!
As did I 
Back in the day, HW2 had a fog system that would draw a flat murk color over your ships when they were viewed from sufficient distance. I can’t say for sure I remember seeing this effect in Remastered, but if it’s still there, I would say use it!
EDIT: Lol, and wandering NPC Lego sharks.
Lego sharks sound good! And so does the fog effect.
The lego sharks need to spit out legoman arms and hands when they die!