Originally Posted by Alaskan Mainship
I have a Mainship berthed in Cordova Alaska - lots of rain. Got to the boat this week and the guest berth carpet is soaked. Main berth has wet floor too (base floor) but not as bad. I obviously have either a leak in the bow and the rain is getting in. no visible sign of any leaks from roof or down walls. coming in and running down the floor. maybe I have a blocked vent somewhere? have caulked the outside to no avail. open to any ideas!!!
Wouldn't be uncommon to have a leak in the rubrail caulking or the actual deck-to-hull joint... with water entering, running down behind any hull liner or whatever, and pooling in the carpet. Can be complicated by clogged or blocked rubrail drains...
You can test this, to a certain extent. Dry the carpet. Flood the exterior at various places along the rubrail... see if the carpet gets wet again.
If that's it, there can be two levels of fix: 1) just recaulk the rubrail and see if that solves it, or 2) remove the rubrail, reseal the deck joint, then replace and recaulk the rubrail. The first worked once for us on one side of the boat, the second was eventually necessary on the other side.
The rubrail caulk is likely not designed to be the waterproofing system on your boat; more like just a first line of defense...