Water Leak 47 Lgt
 

Hi, I use a 47 Lightning 1999 MY one in a while. This boat has som ekind of leak into the bilge. It is salt water, but I can't find out where the water is coming from regardless of how much I search for a leak...... Has anyone experienced this?????????



THANKS. The pumps go about one time every houre. Important to keep the batteries charged!!

I have a 35 Lightning with the same problem. I think I have figured it out, but have not completely addressed it yet.
The seam where the upper half of the boat is mated to the lower half (hull) has a molding with a rubber or plastic strip in the middle of it. I believe that the water comes in at this seam, at the transom, or the holes where the molding is attached.

I pulled the molding out around the rear of the swim step and sealed some unused screw holes and this cut the water leakage in half or less. I have also observed that the water appears when there are a lot of people in the aft part of the boat, or when I am sitting on a beach (bow up, transom deep in the water), or when I am sitting still in rough water so that the seam is at or below the water line.

This winter I plan on removing the metal molding around the rear section of the boat and resealing it completely.

I hope this helps.

David

Thans Dakhanjob,

The case is that the water comes in when the boatis at standstill. The rub rail (seem between hull and deck) is ABOVE the water. The exhaut is above, all other outlets are above aswell... The only places I can think of are the drain plugs, the merc transom (through the boat's transom), generator water pitot pick up... -What more..? On my 29 Fever, it comes though the outlets for the blowers, causing rust. When switch is on, they are rusted so that they do not turn around, and they start to make smoke..... The toggle switch has a build in circuit braker, but this does not cut the circuit.... But your 35 has the outlets on the sides right? I would check the outlets for the through hull exhaust pipes. I notices the water was pouring in when I launched a 35 ICBM the other day. This was also a problem on the 29, so I took them out and put them in with a lot of glue. Then the boat became dry. Great when running hard in rough seas. You don't want the salt water to splash all over the engine, starter etc.

See if you can isolate which side it's coming in (you might be able to hear it, I could)...then read this thread and do what I did...
http://www.offshoreonly.com/forums/s...=sommerfliesby

Thanks a lot. Who can "guess" that it is just that little seal......? I wil try to dry up the bilge completely and then see with a light in the dark where it is comeing from. Those Lowett pumps really is one of best friends now, as the boat is laying in the water... Just need to keep he batteries charged.

Hi Sommerfliesby,
I read your original post when you posted it and had my Merc mechanic replace both seals. They did a nice job using the stainless plates on the outside of the drives. It did help some, as you could see the water marks where some leakage was running in, and the shafts were rusted and had to be replace as well, it was about a $2K repair. But that didn't fix the problem completely for me. When I am in still water and the parting line is above the water line there is no leak, but when I am launching and the transom parting line is below the water, then there is a leak.

I guess I have a winter project comming up, I will deal with this.

check around the tab bolts

I am pretty sure that it is ok on all parts that are under water when the boat is at rest. The water appears when the stern is low in the water, above the parting line on the swim step.

My buddy's 47 started leaking between the transom assembly and the hull. All 3 needed to be resealed.

One not mentioned to quick check, depending on where the leak is would be your AC unit (if equipped). Had a 357 Formula with a weird leak, and it wound up being the filter for the AC unit under the step into the cuddy. Long shot, but easy to check.