Integrated swim platform and trim tabs

[russellh2]

Also look at Google "how to stop boat porpoising"

[cobby]

Sounds like a weight issue more then anything else.
What sort of boat do you have?

4.85m fiberglass with 90hp yam 4s

What boat exactly? Trim tabs and/or foil will only hide the symptoms but won't address the cause. You've got a weight balance issue, fuel tank, battery/s, eskies, whatever you can shift forwards or add forward of centre the better

[sturgeon]

Nothing I can move. I filled sandbags and put them in front and still the same. How much weight would matter?

[smile0784]

Did you check the max rating size for your engine for boat

[sturgeon]

Did you check the max rating size for your engine for boat

Of course. 90HP. The dealer fitted it and optioned it. But it looks I am actually the first customer although they told me then that they had others.