depth finder advice

Tuck · Post by **Tuck** » Sun Mar 29, 2009 7:03 am

i need to get a couple of depth finders for my boat. both of the finders i have now are kaput.

a coupe o' questions: 1. will the old transducer(s) work on a new unit, other than the same make/model? 2. will one transducer work with two display units?

i would actually like to find one that doesn't require any holes...either those already in place or new ones, mainly due to $. (it'll cost to have the boat pulled just to put the thing in, plus the $ for the unit(s), etc.)

so with that, can someone suggest a good unit that doesn't reuquire a thru-hull?

gjrylands · Post by **gjrylands** » Sun Mar 29, 2009 9:28 am

Using the old transducers is not recommender. They are from older units and probably not compatible with newer units.

Most units come with transom-mount transducers. they don't require drilling a hole in the bottom of the boat. You could put a transom-mount transducer on the boat with out taking the boat out of the water. It will require drilling a couple of small holes to mount the transducer. They could me drilled with a hand drill. It wouldnâ€™t be real easy and you would get wet, but it is possible. Another way is to mount the transducer to the inside of the hull and shoot the beam through the hull. The readings wouldnâ€™t be as sensitive but it is suppose to work.

Using one transducer for two depth finders will work if the two units use the same model of transducer. You will need to have a transducer switch to change the transducer to the unit you are operating. Whether you have one or two transducers the two units should not be operated at the same time, unless they operate on completely different frequencies. You could use a unit that uses 200kHz and one that uses 50kHz at the same time, but not if they use the same frequency, or if one uses 198kHz, and the other uses 200kHz, they would interfere with each other.

randyp · Post by **randyp** » Mon Mar 30, 2009 9:29 am

For what it's worth I mounted the transom-mount transducer directly to the inside of the hull bottom on the port side of the engine. Just spooged a big glob of clear GOOP on the surface and set the transducer in it. It's been 6 years and it works fine up to 10 mph then goes ga-ga, but comes back to its senses when I'm back to under 10 mph. If the hull is solid fiberglas you can do this, if not, you gotta go the thru-hull or tansom mount route. But the way the unit is a Garmin 168, which is not made anymore - GPS and Sounder combo.

LSP · Post by **LSP** » Mon Mar 30, 2009 9:38 am

Tuck ..... never used one of these on a Trojan, but I've seen them used on a "bowling ball" boat and they work fine. .... mounted internally. I bought one to try....just haven't used it yet.

http://stores.ebay.com/NorCross-Marine-Products

rossjo · Post by **rossjo** » Mon Mar 30, 2009 10:18 pm

A good color depth finder (Furuno) will use up to 1500 Watts, run 50 & 200 kHZ (200 for < 150kHZ & 50kHZ for > 150') and needs a $200 depth finder - but will show fish and bait balls like crazy! Well worth the $ !!!!!!!!!

Many Trojans have good depth finders, but the head unit goes bad ...

Check what you already have "in-hull". If its a built-in AirMar unit (glued n "puck" on floor), note the model number, and consider buy a depth finder that works with it.

guglielmo6160 · Post by **guglielmo6160** » Wed Apr 01, 2009 8:33 pm

Randy, I did the same thing , it works fine, Im planning on installing another one on the flybridge, and will do the same on the port side ,
I used sticky wax, the type you would use for a toilet wax ring, it works excellent, and the best part of it is that nothing funky grows on the transducer,
I currently have the Garmin unit, with gps the 550 model,
works well, and is stand alone,
Im going to mount another one up at the bridge, so I have same features up there,