Speed/Distance log cleaning

[chucklesR]

My speed/distance log clogged up after only 3 weeks in the crud my boat lives in (Chesapeake Bay).
After almost six months of putting up with only the GPS telling me how fast I was going I went out for s solo sail yesterday.
When the wind finally piped up to 15kts I got moving along at 10.3 kts and that blew crap off the wheel so now it's registering speed and distance again.

How does everyone else do it, without getting water in the bilge?

Seriously, it's only showing about 1/3 the correct speed but I'm hesitant about pulling the log because I have no idea how much water to expect and the Gemini does not have a bilge pump - how much water can I expect to come in while I'm swapping the log for the plug? I'm a reasonably agile guy with excellent access to the through hull.

[dave6330]

I'll have to admit, I have had to pull mine and it IS un-nerving to open it up and have a geyser inside your boat. If you're quick and have the plug in-hand when you pull out the knot-meter, you shouldn't have more than a quart or two of water come in as you switch but you've got to be quick! We have tide lines (?) that are marked by a trail of small debri and every now and then, a twig gets jammed in mine and I have to pull the meter out and clear it. Not something I like doing but I've done it now about three times and haven't sunk her yet.

[Vasco]

Do it all the time. I always pull the impeller if I'm going to be anchored in one spot for more than a day or two. Don't get more than a cup of water in the boat. Soak it up with a sponge. In most boats the impeller is only 18" or so below the water line so there's not a great head on the water coming in. I have a rag ready, pull the impeller at the same time covering the hole, uncover the hole and put the plug in. Some of the newer instrument thruhulls have a flap that stops water coming in.

[Fstbttms]

It is a PITA to pull the transducer, but there is no other fail-safe way to keep it clean. Nature of the beast.

[billangiep]

If you have access and the room you can take a 4" piece of PVC and epoxy this to the hull around the transducer. Cut it off just above the water line. Just a thought?
I have one with a flap type valve it does slow the ingress down substantially. I keep the "O" rings lubed up with a bit of Vasaline.

[Gene T]

It's only scary the first time. But agree, not much water even if you are a little slow with the swap. I use silicon grease on the o-rings.

[SailorMitch]

I use silicone grease on the O-rings, and on the paddle wheel itself. The grease keeps the crud off for about a month at a time. My thru-hull has one of the flaps that limits the amount of water coming in the boat (very little) so I don't worry about it so much now. But my prior boat did not have the flap and you just learn to pull it out fast and get the plug in just as fast. Maybe 2 cups of water would come in on a good day -- or a quart on a bad day (like the time I dropped the plug and it rolled away from me.)

I can't imagine a sailboat without a bilge pump, but that's just me.

[Boasun]

when you clean it... DO Not.... I repeat.... DO NOT use the admiral's tooth brush. Or you'll be on gruel for a year or two if you are lucky.

[CapnHand]

Originally Posted by Gene T

It's only scary the first time.

I wasn't scared the first time. Ignorance is bliss. I decided to take mine out when the boat was travelling at near hull speed. The geyser was startling to say the least.

[camaraderie]

...to slightly change the subject...you don't have a bilge pump????