Perko Thru-Hull Scupper, Transom Mount, 1-1/2 in Hose, 2-1/8 in Max Hull Thickness

Overview

The Perko Thru-Hull Scupper for Mounting through Transom is a transom-mounted scupper valve for draining cockpit, deck, or splashwell water through the hull side of a boat. It fits 1-1/2" hose and uses a 1-7/8" mounting hole, with a 2-7/8" outside flange and support for hull thicknesses up to 2-1/8".

The body is molded white polymer and uses a soft black flapper to help reduce backflow while still allowing water to drain out. This makes it a practical fit for above-waterline scupper drains where water needs a simple exit path through the transom.

This fitting is intended for hose-connected thru-hull scupper use and should not be installed below the waterline. Before installation, confirm the hose size, transom thickness, hole diameter, and mounting location on the boat.

Key features

• Fits 1-1/2" hose for common cockpit, deck, and splashwell drain plumbing.
• Mounts through the transom with a 1-7/8" hole and a 2-7/8" outside flange.
• Works with hull thicknesses up to 2-1/8", which helps confirm fit before cutting or replacing an existing scupper.
• Molded white polymer body suits visible transom installations where a clean white finish is preferred.
• Soft black flapper helps limit water backing into the drain opening.
• Available as the valve only or as the valve with a stainless steel cover for a different exterior finish.

Variants

This scupper is offered in two configurations. Both variants are based on the same transom-mounted scupper application, with the visible cover configuration being the main difference.

The valve-only version keeps the installation simple with the molded polymer exterior, while the stainless steel cover version adds a metal cover at the outside face of the fitting.

• 0323DP: Type Valve Only. This version is suited to straightforward replacement or installation where the molded white polymer exterior matches the boat and no stainless cover is needed.
• 0323DP0STS: Type Valve & Stainless Steel Cover. This version keeps the same scupper function and adds a stainless steel cover for a different transom appearance.

Installation and fit

Check the transom area from both sides before cutting or replacing the fitting. The hose connection, flapper clearance, mounting hole, and nut access all need enough room for a clean installation and later inspection.

Because this is a drain fitting, the mounting location should allow water to leave the deck or cockpit naturally without trapping standing water around the scupper. Bedding and fastening should be handled in a way that suits the hull material and the boatbuilder’s service practice.

Use cases on board

This scupper is a good match for boats that need a simple transom drain for cockpit, deck, or splashwell water above the waterline. It is especially useful when the buyer needs to match a 1-1/2" hose and a compact flange footprint without moving to a more complex drain assembly.

What’s included

• Thru-hull scupper valve
• Nut
• Mounting hardware