depthsounders

[bobflydrum@hotmail.com]

what type of depthsounder should i buy--i would prefer a transducer that mounts inside the hull--do these work on c dorys--i looked at one that said it would not work on a cored hull--any suggestions are appreciated

bob

[tsturm]

[JamesTXSD]

There are a couple other advantages of the transom mount transducers: you can also get one with a temp sensor and a speed paddlewheel. We've had the thru-hull transducers and a through-the-hull transducer on previous boats, and I see no difference in performance. And, no cutting.

Our trimaran had a spot just for a transducer that wasn't cored... anyone know if C-Dory made any provisions like that?

Best wishes,
Jim B.

[thataway]

I blieve that most of the CD 22's had a solid area in the center aft by the drain plug--sump where the bilge pump is, which is solid glass. The CD 25 again where the bilge pump is, just aft of the fuel pump, and the Tom Cat 255 in the STb hull all of the way aft. But each of these areas, means moving the builge pump.

I don't use the paddle wheel sensors, because they are only good for measuring current--the GPS is a more convient speed indicator. Also some engines have a speed function on their digital guages (usually a piot tube, and not real accurate.

I use transom depthfinder sensors, for the boat I keep in the water, but mount a block of Starboard on the transom, then screw the transducer to this piece of Starboard. I do use the water temp function of the transducer.

[Doryman]

I had such bad luck with the transom transducer on my previous boat that I was insistent on a shoot-through transducer for the TC (there is a core-free spot molded into one sponson for this purpose.) I absolutely love this transducer. However, I am adding a dedicated speed paddle wheel & temp module so I can measure current and water temp.

All that said, I have not heard many complaints from other Brats about transom-mounted transducers. The one on my previous boat would only reliably give readings below about 5 mph.

Warren

[Captains Cat]

Warren, did you have to move the bilge pump in that port sponson to install the transducer? Do you have a pix of it?

Charlie

[JamesTXSD]

On our previous boat, we had a paddle wheel speed sensor and GPS - ideal for figuring the effect and speed of current. With the E-80, you can have both and it will figure set and drift for you (not that we need it much these days). I also have an aux GPS right next to the E-80 as a back up (and a comparison). I consider that "nice to know" information... especially when we were up in the PNW and dealing with some of the ripping current you guys have there.

Perhaps a bit OT regarding the initial post in this thread, but it may give some insight on transducer selection and placement.

Best wishes,
Jim B.

PS - And the water temp feature was a plus... 'cause some of you guys think it's warm when the water temp is over 55º!! The only way I'd be going in that water would be kicking and screaming with several large guys working hard to toss me overboard. (Surf water temp here today is 72º and that's way too cold for me )

[matt_unique]

Warren - please do tell us about your transducer - I need to figure out what system I will use when mine arrives. I like the idea of no drilling into the exterior.

[Doryman]

[Doryman]

[thataway]

Our Lowrance transom mounts hold the bottom all of the way up to top speeds in the high 40 knot ranges. I suspect it is the way you mount the transducer. Making sure it is in clear water, is very important.

For thru hull shooting, we make a plywood box (glassed over and to the hull) or use a PVC cylinder which is sealed to the hull. We then use a transom mount transducer, bolted to the side of the container. We then fill the container with mineral oil--We have also used thru hull transducers mounted thru the top of these boxes. This way there is no problem with mounting with silicone or epoxy--bubble trapping etc--and the transducer can be changed out easily. The AirMar does the same thing, by cutting the angle of its plastic box, to conformity of the "V" of the hull and then gluing it to the hull and filling with antifreeze.

We have also just set puck type or transom type transducers on the bottom of the hull (where it was flat), and put lead weights on it. That will work very well in the TC or CD 25 where there is likely to be some small water in the bilge, and the water will be the coupling agent for the ultra sound. The bottom of the hulls is flat in these areas, thus making it un-necessary to cut any angles or make containers. Most of these installations shoot down to the rated depth of the depth sounder--typically 600 to 1000 feet (not that there is much 1000 foot deep water near shore in Florida....

[Al & Pat Parker]

[starcrafttom]

Just a few ideas about transom transducers and poor performance. most TTs are not set up right. I have had many problems my self and have had to learn how to fix them to get the performance I was expecting. picking the right spot on teh hull is the first step. If you had teh dealer install the unit them most likely you got what you paid for or more to the point what the dealer payed for, minumam wage work. Most shops that I have seen, les not included, have the techs do the engines and the shop sweepers do all the rest. its a way to work your way up to sells man or tech, but you get what you pay for most of the time. I have installed six TTs for my self and freinds over the years and placement is the key. lowering the unit just 1/4 of a inch more in to the water can make a big increase in preformance. not having your unit behind a hull strake or a rivet can also make a hugh difference. I have seen folks with the unit toward the outside edge of the hull where it is barely in the water at speed or just in rough water. Its air bubbles that destory your performance of these units. Also remember that glass can hve air in it and that will kill your performance with shoot thru transducer. Thru hulls are the best but who wants to cut a hole in their boat. so get the unit into clean water and towards the center of the boat as much as possible and you will have no problems. except the one problem I have which is the unit keeps getting stuck at 25 ft when I'm in 400ft of water. not sure why that happens.

[Al & Pat Parker]

Hi Thomas,
I'm not complaining about the performance, it has worked quite well. The dealer, Mobile East Marine, knows where they should be placed, and how to set them, I think. No floor sweepers setting up boats there. I just don't like it's drag, and the rooster tail it throws up. I brought that up when the boat was in for the 25hr ck on the engine, and Gene raised it a bit & tilted it to point the beam slightly fwd, which didn't help the tail. I've put another 40 hrs on the boat since then. It's down about 1/4" below the bottom, but topped out in the short slots so I can't raise it. Would like to tilt it, but the pivot bolt is too tight & I can't get a good bite on the nut with any of several sockets I have, while working at arms length down in the water. .
Cooler weather has cut into our time on the water, but it's in the water all yr 'round, ready to go. We sailed every month last yr, several times in Jan. Feb. & Mar. seem to be the worst.

[Doryman]