Boat Leaking Water Through Transom

By Shaira Alano Written by Shaira Alano
Updated on March 29, 2022

A boat may be a vessel that is supposed to ride you through bodies of water, but this does not mean that you should have water idling inside it. If this happens whenever you use your boat, you might want to check on your boat’s overall condition to prevent unwanted accidents as you use it, especially on its boat transom. A boat transom is the vertical section at the rear end of your boat. The height of the boat transom is the reference that we use to know the appropriate size of the boat’s outboard motor, which powers the entire boat.

Here are some indications that there is water leaking through your boat’s transom:

  1. There is water pooling in the posterior area of the hull.
  2. There are evident water stains on the transom plate.
  3. There are water stains on the swivel pins.

To delve deeper into the details of fixing a boat leak through transom, read the entire article below.

How do you fix a leaking transom?

A leaking transom does not necessarily mean that you need a new boat. Sometimes, you can still work on fixing a leaking transom to help you drive your boat again without any leaks. Here is how:

  1. Identify first if your leaking transom is due to rotting. Knock on wood to help you know if it is rotten inside. If you hear a hollow sound, investigate by drilling into the transom. A transom in good condition will give you a hard time drilling because of the density of the wood.
  2. To repair a leaking transom due to rot, you can use products like Git-Rot. This liquid mixture of epoxy and solvent helps make the transom denser again.
  3. If your transom leak is not addressed after using a wood hardener, it would be best to get an expert to disassemble the transom to work on it.

Why is my boat taking on water?

Hose are plastic tubings prone to crack, degrade, or lose their fit over time. Try to inspect your boat’s hoses before sailing to see any need for improving these parts quickly.

Just keep in mind that you will most likely miss spotting lose hoses when the boat is idle. Like the speedometer, some hoses only leak when the boat moves fast.

If you’re on a fishing boat and frequently use Live wells, this might be the problem. Water can run over the top of the Livewell and down into the bilge if it is not well sealed where it meets the deck.

How do I know if my boat bellows are leaking?

Boat bellows are considered as the rubber boots in your boat that keep the water out of the engine’s exhaust, shift cable, and U-joints. When you drive your boat, these areas tilt and pivot to help you maneuver through the water.

When boat bellows wear out through time and use, you might notice that occasional leaks will happen. To avoid further problems with leaking boat bellows, you can follow these steps:

  1. If you have a sterndrive, begin evaluating the problem at the engine. Visually inspect your bellow to see any signs of drying out, cracking due to heat, intense weather, or too worn out.
  2. Bellows that are visibly cracked would be best to replace them to ensure that no leaks will be a problem in the future.
  3. If algae are seen around the bellow, some of the water already within the vessel is seeping out. However, if you leave the boat outdoors and dry, you’ll only be able to see the slime because if the bellows are damaged, water will leak through and get moist.

Where is my boat taking on water?

Knowing the most common locations of water leaks in a boat can help you work on spilling problems before it gets worse.

If your boat is just sitting idle on the water, the likely causes would be loose connections in your hose, drains, thru-hulls, or gasket. This is usually the traced reason for a boat that takes on water. 

In contrast, if your boat takes water while on your way, you might want to check your rub rail if it is loose. Sometimes, the culprit for the leaks is a loose speedometer hose or the cooling system’s connections.

These are not the only causes of water leaking into your boat. If a problem arises and you cannot trace the cause of the leak, you can try looking for loose screws in the hull. A simple tightening of the loose screw can help ensure that water will not come out of it.

It can get into the boat through the top of the gimbal ring, where the steering shaft passes through. A seal keeps the water out, but the shaft is made of hardened steel, which can rust, pit, and damage the seal. The gimbal ring must be removed for this. Before undertaking this repair, get a Service Manual.

A damaged exhaust pipe might also potentially leak water into the boat. The exhaust pipe runs into the exhaust elbow of the engine. When the water leaks from the damaged exhaust pipes, you might overlook some problems from the exhaust elbow as well.

These exhaust pipes are made with an aluminum pipe. Like any other product, aluminum pipes are always at risk of corroding and leaking, especially if not maintained well.