Plastic Transom Drain with Screw Cap (3/4" / 19 mm, short & long versions)

Keep your boat’s bilge dry with this plastic transom drain and cap assembly. It serves as a permanent drain outlet on the back of your boat, allowing you to easily remove any collected water from the hull. The assembly includes a plastic through-hull fitting and a matching screw-on cap, which means you don't need a separate plug – the cap itself seals the drain. The plastic materials are marine-grade and will not corrode, making them well suited for freshwater or saltwater use over many seasons.

This drain comes in two length options to ensure a proper fit for different transom thicknesses. The short version (57 mm length) is suitable for boats with thinner transoms or single-skin hulls where a shorter fitting is sufficient. The long version (83 mm length) is designed for boats with thicker transoms or double-skinned hulls, providing enough threaded length to secure firmly. Both versions accommodate roughly 18–19 mm (3/4 inch) diameter drain openings, which is a common standard for small boat drains. Each has a wide flange and is supplied with a locking back nut for secure mounting.

• Quick bilge draining: After a day on the water, simply unscrew the cap to let water drain out from your boat’s bilge or any compartment. It’s perfect for trailered boats – drain rainwater or wash water easily when on land.
• Livewell and baitwell use: Can be installed as a drain for live bait tanks or coolers on board. The screw-cap lets you keep water in when needed, then release it when you’re done.
• Maintenance-friendly: The cap is tethered (optionally you can attach a lanyard) or easily stored so it won't get lost. Opening the large cap also provides access if you need to rinse out or inspect the drain hole for debris.
• Affordable and reliable: This plastic drain is a cost-effective alternative to brass or stainless drains, while still providing a reliable seal. It’s ideal for small fishing boats, inflatables, and personal watercraft where weight and cost are considerations.

Installation is straightforward: insert the drain fitting from the outside of the transom, apply a marine sealant under the flange, and tighten the retaining nut on the inside. The screw cap can then be tightened by hand to seal, with an O-ring or gasket ensuring no leaks. By using this transom drain assembly, you gain an easy and efficient way to manage water in your boat, helping prevent damage and prolonging the life of your vessel.