T-H Marine Low-Profile Twist-Out Deck Plate, 4"

T-H Marine Low-Profile Twist-Out Deck Plate — 4"

When space is tight and a clean, flush deck surface matters, the T-H Marine Low-Profile Twist-Out Deck Plate is the compact solution. At just 4 inches, it’s sized for smaller access points — wiring pass-throughs, small inspection ports, and drain plug locations — where a larger plate would be overkill. The twist-out closure is fast and tool-free: a simple quarter-turn releases the lid, and the fully overlapping lid design combined with a positive o-ring seal keeps water out when it’s closed.

Hidden mounting fasteners keep the above-deck surface smooth and snag-free, and the low-profile design sits closer to the deck surface than standard raised-lid plates — reducing the chance of catching lines or gear.

Features

• 4" twist-out closure — tool-free, quarter-turn operation
• Fully overlapping lid with positive o-ring seal for a watertight fit
• Low-profile design sits flush and close to the deck surface
• Hidden mounting fasteners for a clean, snag-free finish
• Lightweight construction

Best Use Cases

Best suited for small, frequently accessed ports where a low deck profile and fast tool-free access are priorities — wiring grommets, small inspection ports, and livewell or bilge access points in tight spaces. The twist-out mechanism is faster to operate than a screw-out closure, making it a good choice for ports that are opened and closed regularly during a day on the water.

Parts Desk Insights

The 4" measurement refers to the plate’s outer diameter — confirm your cutout size before ordering, as the required hole diameter will be smaller than the OD. For a larger watertight option from the same brand, see the T-H Marine Sure-Seal Screw-Out Deck Plate, 8". For a screw-down style in a mid-size format, see the T-H Marine Screw-Down Deck Plate, 5-5/8" OD. For larger hatch-style access, see the T-H Marine Sure-Seal Non-Locking Access Hatch, 13" × 23-1/4".