What are these under my floor board?

[footbrake]

In the cabin of my Chris Craft Catalina 251, under the floorboard,attached to the hull there are a couple round things about 3" in diameter with a wire coming out of them. What are these.

Also, I'm a little concerned that I always have about 1"-1.5" of water in my rear bilge. People tell me that it's really normal with my type of boat as the shaft seal going through the hull will drip and the rudder shaft coming through the hull aft will leak a little. It's never enough to activate the 2 bilge pumps I have in the rear but still a concern. Thanks for any help with my 2 questions.

 

[SkiGuy1980]

I don't know why there would be two, but the round thing with the wire sounds like it could be the transducer for your depth gauge.
As far a water in the bilge on an inboard - yes, the packing around the prop shaft has to weep just a bit to maintain its seal. I didn't mess with it much, but my Supra had the same set up. I don't recall it needed a large drip... or one that would accumulate even a half inch in the bilge overnight. The seal around the rudder shaft was much tighter and waterproof. It didn't have the same packing material (you aren't having to cool a high RPM shaft).

 

[footbrake]

My understanding is the depth is being run from the Garmin unit on the dash with the GPS receiver on the front deck. I have a shaft seal with a water line going to it from the manifold to cool it.

 

[roscoe]

My understanding is the depth is being run from the Garmin unit on the dash with the GPS receiver on the front deck. I have a shaft seal with a water line going to it from the manifold to cool it.

The garmin unit, or any other brand, will still need a transducer in the bottom of the hull, or hanging off the back of the transom, in order to read depth.

 

[footbrake]

Where would the transducer be connected to my Garmin unit? The only wires to it are hot,grd, and the wire to the receiver that I have out on the front deck.

 

[Scott Danforth]

without a picture, we are just guessing

could be a bonding point (is the wire heavy and green with a yellow stripe?)
could be a depth finder transducer (is the cable heavy and black or grey?)

 

[footbrake]

I'm going to get some pics tonight

 

[footbrake]

Here are some oics and there are 2 thick black wires coming out of my Garmin unit.

 

[mr 88]

Those are your transducers,leave them alone. Your dripless prop shaft seal needs to be tightened up slightly. There should be about 3 allen head bolts in the collar/outside ring. those are loosened up a bit. Then either try to move the ring with your hand towards the stern or take a soft face hammer and tap it back until it stops leaking. If you go too far the carbon in it may wear prematurely and you will see some black residue seeping out over time if that happens.At least that's the way mine works,,not sure what brand you have but they should all work on the same principal and you may want to make sure there is nothing clogging the hose at the manifold to keep water from flowing to the collar. Rust particles have a tendency to accumulate there.

 

[Old Ironmaker]

Those 2 black pucks are definitely through hull transducers. Transducers are not always on the transom, I have one at the front of my StarCraft hanging on the elec. trolling motor as well as 2 on the rear transom. I know zilch about I/O's.