How do you paint water?

[miltiades]

I made the base for this Catalina model with splash/wake made from green stuff formed on a CD, then painted to match a crumpled garbage bag (Bag looks surprisingly like water under an overcast sky)!  I painted the base black mixed with a little green;  foam was dry-brush painted almost white with a touch of yellow; then many layers of spray gloss clear.  No blue paint did I use!

I thought the picture was of  a REAL Catalina 

[SteveBurt]

For the bases of my ships I use a deep green/blue (phthalocyanine green). I then cover that (and the label on the base) with acrylic texture paste, which goes on milky but dries clear. texture it using a palette knife.
Quick dry brush with off-white for wake, bow wave, if any, and wave tops.
Sample of some of my 1:3000 WW1 ships below