To fix boring water fights try removing all Dock auto healing maybe having to use villagers or fishing ships to repair will make it more skill and micro.
This also allows partial raids to be effective. When you kill half the health of a fishing ship you can come back and expect a low health fishing ship to kill. Right now all your previous damage is irrelevant when you take the next water fight. With no res or APM cost to the other player he has BRAND NEW ships again. Unless you kill ships fully. Because of damage not sustaining it requires to have a better water army or better demo hits to win each fight it seems.
Instead of waiting for a full water rework- you can do this without new ship assets.