Depth sounder with no thru-hull?

[rlevy]

Does the power or frequency of the transducer affect how well it will shoot through the hull?

[T34C]

I WOULD NOT RECOMMEND USING EPOXY OR ANY TYPE OF SILICONE for this application. I have installed units in this manner in my last 4 boats and will say that it works very well. All of the advise above is spot on with the exception of what material to secure the "puck" in place with. Silicone/RTV is designed to be flexible. It will absorb some of the signal that you are trying to shoot thru the hull. Epoxy will hold very solidly, but if you ever need to remove it, it aint gonna happen. I would recommend using polysufite caulk when attaching the puck to inside of the hull. apply nice (1/2") glob to bottom of transducer covering entire puck, making sure there are no bubbles, and press firmly into place. caulk will squeeze out the sides. Let sit for 24 hrs. before use. The caulk will remain somewhat pliable in case you ever need to remove it, but does not exhibit the flexibility of silicone based products. Obviously some have used RTV with success, so it is certainly doable, just not what I would recommend.

[SailorByFate]

I have an in-hull transducer that I installed myself. The old transducer could not be removed without a haul out, so in-hull was the obvious choice. I was quite surprised to find that it can reliably give us a depth reading to 500 feet here in Puget Sound. Most of the time we get a solid reading to 600 feet.

Ours is a 1972 (I think) Cascade hull, non-cored of course. Fiberglass compositions vary, so I don't know if you will get the same results.

[wchevron]

how do you know if your hull is cored or not. should you call the manufacturer?

[Maddog046]

If you need a depth sounder for just the season, go with the Prirana Max Fish Finder. I epoxy the puck to the inside of the hull and works great. All for about $60. When you haul, put in the system you want. I even spliced the tranducer cable to get it to my helm. Easy to do. It's a 2 wire signal cable that I soldered. It reads to 600'. When I am heeled over I do get some false readings on fish hits about 10' off the bottom at depths over 100'. I ignore these. Couldn't be happier for the price.

[sailingdog]

The only problem is if the boat has a cored hull or a void in the layup. Either will stop a transducer dead.

Originally Posted by Maddog046

If you need a depth sounder for just the season, go with the Prirana Max Fish Finder. I epoxy the puck to the inside of the hull and works great. All for about $60. When you haul, put in the system you want. I even spliced the tranducer cable to get it to my helm. Easy to do. It's a 2 wire signal cable that I soldered. It reads to 600'. When I am heeled over I do get some false readings on fish hits about 10' off the bottom at depths over 100'. I ignore these. Couldn't be happier for the price.

[TrueBlue]

Originally Posted by wchevron

how do you know if your hull is cored or not. should you call the manufacturer?
__________________
wchevron

rhode island
'78 c-30

I believe the '78 Catalina 30s were built with solid fiberglass hulls below the waterline - at least according to a friend who has one. But, check for certain with either the mfgr, or the C30 owner's association.

[artbyjody]

And for more information Don Casey's How TO

[sailingfool]

Originally Posted by wchevron

how do you know if your hull is cored or not. should you call the manufacturer?

The Catalina should be all solid glass.

You can identify core areas, in either a hull or deck, by the change in laminate thickness where the core is present, the laminate gets thicker, producing a sharp ridge at the transistion point. If you look around the underside of any cored deck (which would inlcude about 99 out of 100 decks), you will see the core ridge, usually several inches in from the toerail. Hopefully far enough in soy the stanchions bolts go only through the non-core laminate.

[artbyjody]

Actually, it may be cored - my 1980 C-27 has a plywood cored bottom that tapers off at the waterline to the deck as solid GRP... I installed my own ducers so pretty positive on that one...