Why does my boat do this?

[NGABaldEagle]

15'6" Venture bass boat 50 hp merc. 1987 package.

I have the foil on the foot.
I have power tilt.

I adjust the trim down and the boat planes good and goes maybe 35 mph.
The bow is down and the boat rides nearly level.

I adjust the trim up and the boat speeds up slightly but the bow raises.

If I raise slightly more it starts bouncing in the water, trim back down a little and it goes back level and smooth.

Is that normal?
Any suggestions to keep my bow higher, speed up, and not bounce off the water?

 

[Drowned Rat]

Re: Why does my boat do this?

Completely normal.

 

[Chris1956]

Re: Why does my boat do this?

That is how a high-performance hull is supposed to behave. The best performance will be when the boat doesn't quite bounce (or porpoise).

 

[steelespike]

Re: Why does my boat do this?

You can try going beyond where it starts to porpoise.you may get to the point where the bow will stay up.As you trim up do it just a little at a time and let it settle before proceding.You might try it without the foil it will likely be slower to plane but trimming may be easier to adjust.And your speed may be better.

 

[kenmyfam]

Re: Why does my boat do this?

Your trim is for adjusting to the "best performance" point. You have to "fine tune" it for your particular set up.

 

[NGABaldEagle]

Re: Why does my boat do this?

Duh! Porpoising! Now I get it.

Im the local idiot up in Cumming so it takes me a while to get it.

I see what you mean by your suggestions.

Yes. Performance hull is what it is and Its doing what its suppose to do.

They are suppose to be able to ride on plane almost level correct?

FOr high speed visibility this scenario is optimal correct!

Thanks guys.

 

[Texasmark]

Re: Why does my boat do this?

Depends on the specific hull whether or not it planes out and runs flat. A flat bottom boat will run flat. A heavy deep V I/O will usually arse drag.

Ever notice how they cut the bow down on some hulls (older SeaRay I/O's for one, older ProCraft for another, Rivertrail for a third). They do this so that the operator can see over the bow which is in the air most of the time.

Course when you are in heavy seas, you wish that they would have left the bow alone and had given you that extra height that they cut off.

Mark

 

[LubeDude]

Re: Why does my boat do this?

Depends on the specific hull whether or not it planes out and runs flat. A flat bottom boat will run flat. A heavy deep V I/O will usually arse drag.

Yep, it depends on the hull and HP!