Skimmer ducer losing bottom

[The RealRookie]

Ok, boat has a 25hp 4stroke on it and it doesnt go very fast!! Maybe 20mph!

Ive had the boat a few years and am getting pretty sick of losing the bottom when running. Not sure what the problem is, but the ducer is placed by the manufacture.

I can regain the bottom by turning hard to the right, or by slowing about half throttle, but lose it again when going back to full throttle only when ive gained some speed.

Any suggestions or questions?

 

[bjcsc]

Re: Skimmer ducer losing bottom

I'm no pro, but it looks like it's mounted too far from the centerline to me. You're losing the bottom because it's losing clear (as in non-turbulent) water. Easiest solution is to install a shoot-thru. Mine keeps the bottom at 50+mph...

 

[The RealRookie]

Re: Skimmer ducer losing bottom

Aw no, a shoot-thru!?!? I thought they didnt work on aluminum boats?

 

[Silvertip]

Re: Skimmer ducer losing bottom

The transducer is indeed losing clear water. Look at the hull design.

 

[bjcsc]

Re: Skimmer ducer losing bottom

Aw no, a shoot-thru!?!? I thought they didnt work on aluminum boats?

I don't know why they wouldn't. All they need is a dense substrate. I have heard of problems with foam core hulls but never any with aluminum. But, I don't know how all aluminum boats are constructed.

If there's an airspace between two pieces of aluminum for the hull, it won't work...

If you set your motor down, you can see where it was designed to run. I bet your transducer is above that point...

 

[eastern27]

Re: Skimmer ducer losing bottom

It need to go to the center, you have a lot of air running down the starboard side of the hull along the V. Buy a 12"X 2" X 1/2" piece of King Starboard and mount that along the rake of the transom. Mount the transducer to to it and try it. Keep moving it until you get the performance your looking for.

 

[The RealRookie]

Re: Skimmer ducer losing bottom

Here are some better pics. I think maybe i should trymoving it all the way down and then try tipping it a bit if that doesnt help at all?

 

[bjcsc]

Re: Skimmer ducer losing bottom

Definitely move it all the way down since it has some adjustment. I don't know about tipping it - depends on how it sends the beam out (I don't know). Might need to be level...Someone who knows that style of transducer better than me is going to have to chime in...

 

[JB]

Re: Skimmer ducer losing bottom

The hull shape is channeling air to the transducer. It is in the worst spot for that.

I would move it outboard to get out of the bubble stream.

100 to go.

 

[The RealRookie]

Re: Skimmer ducer losing bottom

Wow, lots of opinions. Something i want to avoid is putting holes all over the boat. Ill try adjusting it all the way down, and if that dont work ....

Get the suggested board to run along the bottom edge of where it is and try moving it around till it gets happy......but

can we please agree that i can leave it on the back, as it is, and not have to mount it under to the next step?? Please?

 

[eastern27]

Re: Skimmer ducer losing bottom

On my 19ft aluminum hull I was on my 3rd sonar unit (1986 - 2000) before I used a mounting board . 2nd try on the 3rd unit I got in clean water, no problem at wot 35mph. On my 22ft CC, glass hull (25 deg. deadrise) I put on a mounting board 1st. 2nd try in transducer position got me a good bottom lock in 300+ ft. at 38knts. I couldn't tell from the picture, is your trailer pitched down to the bow? If not try repositioning the transducer level so it's 2 or 3 degrees forward of hull when the boat is level. Yours looks like it's angled to far up. That may be the whole problem.