boat 'jumps' on the water

[popey]

hi there

had just a great day on the boat. The weather was nice, not windy and the water calm. Although my boat sort of 'dances' on the water whil passing the 20 knots. At full throttle 32 knots, the boat hits hits heavily. Has this to do with the trim or just, that the boat is small? Does anyone have a short description on how much to trim and at what point? My trim indication only works when I lift it out of the water.

Thanks for your help.

Best popey

 

[Steve Mahler]

Re: boat 'jumps' on the water

You dont mention what kind of boat, but 32kts is fast, sounds like you need more force on the bow - either trim down your outdrive or push down with tabs. Try just a little at a time while running on plane.

 

[popey]

Re: boat 'jumps' on the water

You dont mention what kind of boat, but 32kts is fast, sounds like you need more force on the bow - either trim down your outdrive or push down with tabs. Try just a little at a time while running on plane.

It is a Starcraft American 18

 

[Davem3]

Re: boat 'jumps' on the water

actually may we see a pic of the back, please????

is this a I/O or a outboard motor please????
this model Starcraft had it designed both ways ..........

I do concur with Steve 100% though .......................

trim the tabs down a little and trim the motor down, not up

 

[popey]

Re: boat 'jumps' on the water

hi there - thanks for your replies.

It is a inboad engine Mercruiser 165 IL6. Do I understand that right, down means outdrive into the water and up means towards the sky.

So when I start the trim is down, for the middle range speed the trim is slightly up an at full speed I do switch it down again. Do I understand that right?

Best

popey

 

[WIMUSKY]

Re: boat 'jumps' on the water

Yep, trim it down until the porpoising(bow going up and down) stops.

 

[Shabah 182]

Re: boat 'jumps' on the water

The condition you are describing sure sounds like porpoising. A set of 120 dollar Nauticus smart tabs will solve your problem!