Although not (yet) having done water myself, I have of course seen a lot of modelled water over the years - watched closely and learned a lot - and have concluded there are two basic ways to do it (that I really like, anyway):
- Completely opaque, "Faux-Ocean" painting, or;
- Flooding/embedding in a clear base, having some actual depth to it.

Of the latter, really one of the best examples I've ever seen was right here at ModelFleet:


Phil Fuss' U-505 was set into a fairly thick, blue (styro- or polyurethane foam?) base, flooded all around with acrylic(? IIRC) gel. Note some blue light - transmitted/reflected from the base - diffuses up through the gel, creating an actual clear-water effect. I can't remember if this was the appearance as-finished or still in progress, but one could additionally drybrush opaque, white foam - hitting just the tops of the surface textures - for a true, 3-D effect.

For a really good (recent) example of a completely "faux-finish" ocean, I was able to come up with the following, from Steel Navy:


Kostas Katseas' Yamato is just one (relatively recently) from his long line of BB builds (at least), having consistently very good - and yet further improving, IMHO - "faux-ocean" depictions. All of which appear to begin with a uniform, dark base color - blue, -green or even close to black - the precise color seeming almost not to matter all that much - simply laid down. Next - apparently just as for Phil's U505 diorama, above - a (now thin) layer of clear gel is presumably spread over, with the desired surface texture.

Now comes a key feature: depiction of (at least some) subsurface bubbles - which I would call the "Under-Wake" - in various shades lighter than the base/background. For deep blue/black backgrounds, the effect is much better (and also scientifically accurate) if the Under-Wake is distinctly greener - think: the aqua-blue seen off tropical beaches - just exactly as seen above. Although this can be overdone (as, IMHO, on this earlier build), still it will remain far superior to neglecting it entirely - and/or simply whitening the background color which, over deep-blue water will create a distinctly (and implausibly) "icy" look. (I won't offend anyone by showing any examples, which are everywhere and very easy to find). However where the background color is already very green (or even brown), then just lightening with white - the Under-Wake bubbles getting a sort of "washed-out platinum" color - seems to (me to) look best and I wouldn't push it any further towards the yellow, or it will probably just look like mud.

Definitely apply the Under-Wake - blending/drybrushing it in cloudy patches (as above) and/or perhaps including some spiral/corkscrew patterns - before painting the surface foam (see below). A lot of modellers seem to pay little, if any attention to this entire "layer", and their water looks (IMHO) like sh**, accordingly.

Finally, surface foam is (apparently best sparingly) painted in straight-white paint - depicting breaking wave-fronts in solid white, followed everywhere by "swiss cheese" sort of webbed patterns, outlining ovals and circles of the clearer/deeper background. If you can make the wake surface (gel) texture to already to mimick these curving strands of "webbing", so much the better - then just dry-brush the high points - but otherwise I have seen this very effectively dry-brushed straight onto a smooth surface.

For the breaking wave-fronts I have often seen cotton used - including for bow waves, as (undoubtedly embedded in the gel construction) seen above. But IMHO, unless physically required to hold up the feature (as, again, apparently for the huge bow wave above), it adds little, if anything further - and can often detract - compared to skillful painting of a simple blob of gel: solid white along its leading (breaking) edge, blending/drybrushed over the Under-Wake color, trailing. (Just like many WWII USN false bow waves.) Likewise for whitecapping, in depictions of rougher seas.

As you can see, I've been "mentally modelling" water - trying to understand what and how something does or doesn't look right - for some time now. I deliberately chose the above as they are in 1:700 scale, just like you are planning Donny, and it'd be great to watch/kibbitz as you take a crack at it!

Cheers,

-Matty