How To Unclog A Scupper On Your Boat

Scuppers are designed to drain water off the vessel, not bring it onboard and into the bilge. If you install drains to the bilge you will have effectively created a controlled sinking of your vessel. I suggest managing the water on the deck and keeping it out of the vessel. If your scuppers are round you can get rubber flaps for the exterior or stepped rubbers plugs that wedge in from the deck side. Plugs will keep water from coming in but they also will not allow water to go out. Attach a length of line to back of the plugs and you can pull them as if needed to drain the deck. If your scuppers are square (rectangular) install the exterior rubber flaps. That may be enough to solve your problem or at least make it manageable. The exterior flaps will not keep all the water out, but then they do not have to. They will keep most of it off the deck.

Boats are made to be on the water, not to have water in them. But often times, that’s what can happen when a scupper gets clogged. A scupper is designed to allow water that gets inside the boat to drain. Luckily, unclogging a scupper is a simple process.

Instructions on how to unplug a scupper:

1. Take the boat out of the water. It’s hard to drain water from a boat when the boat is sitting in water. You can unclog a scupper at your boat dock by simply using the lift to get your boat out of the water, or you can do this on land with your boat on a trailer.

2. Locate the scuppers. These can be located anywhere from one inch to four inches above the water line.

3. Identify the clog. If it’s one large object, you might be able to remove it with your fingers. A clog that consists of smaller objects like hair, fur and grass that may take a little more work.

4. Run a hose into the scupper. You should use a hose that is flexible enough that it can run into the boat and into the scupper without restricting water flow.

5. Flush the scupper with a heavy stream of running water. You may have to periodically remove the hose and shift the clog around with your fingers or with a sturdy object.

6. Continue flushing the scupper until the clog is gone. You’ll know the clog is gone when the water runs clear of all debris.

7. Install flappers to prevent clogging in the future. Flappers fit on the outside of the boat and prevent dirt and debris from entering the scupper from the outside. These flaps can be as simple as rubber fastened at the top or they can be as complex as stainless steel mounts. The option you choose to install is up to you.

TH Marine flapper scupper repair kit fits a need in that many scuppers suffer the loss of the flapper from a variety of reasons. These range from warping due to UV exposure to being ripped from the frame by water even some animals eating at the rubber material. TH Marine decided to address this need by offering this kit that contains two each of the most popular size flappers.