Thru Hull Transducer location?

[strick]

I'm getting ready to install my GPS/fishfinder on my 1975 23 cc. It has a fairing block that is about 18 inches long and 3 inches wide. Where is the best location to mount this Thru Hull Transducer? Thanks in advance

Strick

[Captn C]

I wouldn't do it. I have three thu hull trans ducer in the bottom of my 1999 25' SeaCraft and I wish I didn't. None of the bottom units will read over 20 knots.

IMO-Either do a in-hull or the transom mount. Once you have a hole in the bottom you'll always have one.

FYI two are Lowrance and one is Furuno.

[NAHIM]

Strick,

What model GPS are you installing.

[ScottM]

I agree with Captn C. I have a thru hull for my Koden color FF and it doesn't read above 18-20 knots. My buddy has a Furuno FF with a transom mount on his Hydra-Sports CC and his reads all the way up to WOT, about 40 knots. Had I mounted the transom mount for my other FF (a Garmin) correctly, I'd probably get the same results but I mounted it too high and it stops reading over 20 knots too.

[RS]

FWIW, I've just converted my skimmer transducer into a shoot through hull after the plastic transom bracket broke. I used 4 inch PVC sealed against the hull with playdough to create a temporary well in the bilge, dropped in the transducer, added water and voila, excellent reading FF at WOT of 35 knots.

When mounted on the transom, I lost the signal at about 30 knots, which was pretty respectable too.

[strick]

Hmmmmmm.... I have a Furuno 1650... It worked fine on my other boat.. installed midship about even with the consel. Is there something about the Seacraft the way it rides that gives the transducer turbulence?

Strick

[Dave Hirshberg]

Just My opinion but I'd sooner go transom mount or shoot thru. An 18 inch block anywhere near the motor is asking for trouble( possible cavitation or obstructed cooling). Its going to be tough to get that thru hull transducer as far forward in this boat as it may have been in your other one. The way the stringers , livewells , and fuel systems are layed out just makes it really hard in a 23.

[RS]

I don't think there is an inherent turbulence issue. It just seems that there is not much board experience with the best place to install a thru hull since others found easier ways to install a transducer. Also, since this group is restoration oriented, there may be an general bias toward not drilling holes through the hull unless there are no reasonable alternatives.

To actually answer your question about the best place, common wisdom is that thru hull transducers generally work best on planing hulls toward the transom and on the deepest flat section of hull. This would be about midway between the keel and first vertical rise.

Also be aware that your fairing block may not fit properly if the deadrise at the installation location is not the same at the prior boat's.

A final thought is that a through hull affects trailerability of the boat, which might influence a future sale.

Hope this helps.

[strick]

Darn... now I dont know what to do... I guess I'm going to bring back the new Fairing Block I just bought for the SC and get a transom mount transducer.. those thru hull's are a pain in the A$$ to install anyway. Thanks for the input I appreciate all the help [img]images/icons/smile.gif[/img]

[Ed]

Strick-

I have a Garmin 188c GPS with Sounder and a Furuno FCV-600L on my boat. The Garmin was a transom mount and never really worked right, except when at rest. THe Furuno is a shoot through the hull bilge mount and works all the way up to WOT at 45mph.

I just exchanged the Garmin 'ducer for a shoot thru the hull puck and will be installing it shortly.

If I were you...I would get the the shoot thru the hull type 'ducer. When installed correctly, they work great.

The problem with transom mounts is.....a lot of interference from air bubbles from the engine, hull wash, and trim tabs. By the time you figured out the best position....you would have drilled about 5 sets of holes in your transom.