Thru Hull Transducer location?
 

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

Re: Thru Hull Transducer location?
 

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.

Re: Thru Hull Transducer location?
 

Strick,

What model GPS are you installing.

Re: Thru Hull Transducer location?
 

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.

Re: Thru Hull Transducer location?
 

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.

Re: Thru Hull Transducer location?
 

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

Re: Thru Hull Transducer location?
 

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.

Re: Thru Hull Transducer location?
 

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.

Re: Thru Hull Transducer location?
 

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]

Re: Thru Hull Transducer location?
 

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.

Re: Thru Hull Transducer location?
 

I just installed an Airmar P66 with temp and speed on the transom. It works terrific. The only signal loss is on hard turns, like MOB drills. The template was a big help in getting the unit vertical and at the right relationship to the hull.

http://www.foodmachinery.com/airmar%20p66.JPG

Re: Thru Hull Transducer location?
 

This discussion took place in July and had a different response to it, you might want to read this thread.
http://www.classicseacraft.com/cgi-b...c;f=1;t=000611
FellowShip [img]images/icons/cool.gif[/img]

Re: Thru Hull Transducer location?
 

Gary,

We don't have too much debris here. BUT, I will admit that the plastic bracket is a little flimsy. I'm going to re-install it with s/s washers and 4200 behind it against the hull to firm it up.

Anyway, still works great. The speed was off on the Garmin 160 Blue, but it has a calibrate (w/ GPS) feature that works good. The units reads the bottom well up to the 45 MPH top speed.

Re: Thru Hull Transducer location?
 

Additional comments:

The hull shown is a 2003 Boston Whaler Outrage.

I mounted on the Port side because of the swim ladder. The location shown was the ONLY place that didn't interfere with the tiedown strap or the bunk. Dumb luck, I guess.

You guys havn't discussed the temp probe that is ineffective when shooting thru-the-hull.

[ October 01, 2003, 04:17 PM: Message edited by: Otto Cuyler ]

Re: Thru Hull Transducer location?
 

Otto, I have the same set up on my 23WA and it works great, BUT!, I have had to replace it twice,the side brackets break, I think due to junk coming in under the hull. We have a lot of that here is the islands, especially during and after the gill net seasons, they seem to gather up everything in their nets and it gets released in mass, especially ell grass. Then we get a lot of wood when the rivers rise and wash into the saltchuck.

Re: Thru Hull Transducer location?
 

“A General Observation”
I have been thinking about the ducer thing and thought I would put this general comment into the mix.
Over the last 25 years we have seen a ongoing improvement in our fish finding equipment I know for myself I must have installed at least 8 to 10 different fish finders on my boats each one was better than the one before it. I now use the Furuno 600 and love it. This unit, if it was possible to buy it 20 yrs ago would have cost probably $15,000 or more. The point I want to make is that although the fish finder has greatly improved for the most part we as “small boaters” have stuck with little poor quality transducers and not kept up with these new and powerful fish finders need of a top quality ducer to do the job correctly. If we are going to use great fish finders then why use crappy ducers for that equipment. Kind of like buying I brand new high speed computer and only having 4 megs of memory in it. The transducer is a very important part of the overall success of your depth finding if you are going to use a cheep ducer then just buy a cheep depth finder but if you are buying a $750- $1,500 unit then don’t blow it with a junk ducer. Remember the Hupple Telescope.
FellowShip [img]images/icons/rolleyes.gif[/img]

Re: Thru Hull Transducer location?
 

ment to say Hubble
FellowShip

Re: Thru Hull Transducer location?
 

Here's a photo of the location I put Mine.There was an earlier post as to where to mount a transom Ducer.Put it on a piece of acylic so I can move it around.Only screws go thru the hull & the acrylic.I also have a shoot thru style & will try the rest of the ideas here!
Hoping to splash Her THIS WEEKEND Weather Permitting.
Scream'n reels' [img]images/icons/cool.gif[/img]
http://www.frenzie.com/SeaCraft_photos_003.jpg

[ October 02, 2003, 01:02 PM: Message edited by: Capt. Brad ]

Re: Thru Hull Transducer location?
 

Capt Brad,

Why are the trim tabs located so high on the transom? Or does it just look that way?

My Furuno is theFCV600l and it has the thru hull "football" shaped transducer. Once you go over 20knots it's history.

I bought the boat used and thought they would have performed great. Boy was I wrong. It doesn't have the fairing block on it and I don't know if I want in. When they DRILLED the big hole in the bottom of the boat they put in front of the strarboard engine. The water pressure gauge for that engine fluctuate even with a brand new water pump. That engine also turns a few more rpm at WOT, which I don't do often.

During the off season I plan to have all three hole in the bottom fix'd and do something else.

[ October 02, 2003, 03:12 PM: Message edited by: Captn C ]

Re: Thru Hull Transducer location?
 

Captn C the trim tabs were originally inboard.I moved them to the outer edge as I was told the further out they are the better,I also as per Bennet went one size larger.Due to the stern heavy SeaCrafts.Let Me tell Ya sumpt'n. Hold on & lightly push the trim !They are sensitive but they work great/fast !.I have not splashed Her yet so I don't know ?? (THIS WEEKEND)They are about 1/8 " above the bottom hull. Cut around the scuppers.I have scores of photo's on My site.I can send a link.I don't have some photo's of the repair/before work as I have to scan them.
Boy do I miss the Red Snapper Fish'n,Nice photo's on Your site.
Scream'n Reels' [img]images/icons/cool.gif[/img]

Re: Thru Hull Transducer location?
 

Great comments.
I brought back the fairing block and got a transom mount. I'll need temp because were are going for tuna on Tues. I'm keeping my Thru Hull transducer and may mount it in the future if I'm not happy with the Transom mount. I guess every boat is different in it's own way and what worked for one boat may not work for another boat. Kinda like finding the right load for your deer rifle. I never had a problen with the thru hull in my other boat the way it was mounted.... worked at all speeds and turns. I just did not like the fairing block sticking down because I envisioned it hitting a log or getting on the trailer somehow. 5200 is some strong stuff and I don't think you could blow the fairing block off with TNT once it is mounted and cured. A buddy of mine is trying another way to mount his thru hull. It's a big transducer and the fairing block would have been too big for his Formula 233 check it out. http://thehulltruth.com/6/ubb.x?a=tp...634#7446009634

Re: Thru Hull Transducer location?
 

Thanks Capt Brad.

You're right they do work better on the out side edges of the transom. I had to use heavier tabs on my Robalo. My fish box is in the port bow and when I would compensate for the added weight it "cupped" the port tab. I'd had them on the boat for over a year and Bennett replaced them for free.

I hope the ol' Robalo is sold. I got a good bite oni it this week and I'm going to take him for test ride Sunday. It's a nice boat, but it ain't no SeaCraft!