Lewmar — Size 8 Opening Stainless Steel Portlight — 239-393820862

Lewmar Size 8 Opening Stainless Steel Portlight (393820862)

The Lewmar 393820862 is a Size 8 opening portlight with a polished 316 stainless-steel outer frame, chrome interior trim, and a grey-tinted acrylic lens. The opening design brings ventilation to the cabin below deck, while the handle-and-hinge system keeps the lens clear of obstructions, presses evenly on the seal, and is designed to resist vibrating open when secured. A flyscreen is supplied as standard.

Key Features

• Lewmar part number: 393820862
• Size: 8 | Version: Opening | Shape: Elliptical
• Outer frame: Polished 316 stainless steel
• Interior trim: Chrome
• Acrylic: Grey tinted, 10 mm (3/8 in.) thick
• Overall dimensions: 196 × 452 mm (7-11/16 × 17-13/16 in.)
• Projection: 4 mm (5/32 in.)
• Weight: 1.9 kg (4.18 lb)
• UPC: 743683110320
• Flyscreen supplied as standard

Compatible Applications

• Marine cabin-side installations where a Lewmar Size 8 stainless-steel opening portlight is specified
• Lewmar specifies a minimum mounting-surface (hull) thickness of approximately 9 mm and a maximum of 30 mm for the current stainless-portlight range

Sizing & Fitment

The Size 8 portlight uses a unique elliptical cut-out. Lewmar's main specification table directs installers to the dedicated Size 8 drawing rather than listing the cut-out dimensions, so confirm the vessel opening against the Lewmar Size 8 drawing before modifying the cabin structure. Do not use the outside frame dimensions as the cut-out template.

Installation Notes

• Lewmar specifies installation on a flat surface within approximately ±1 mm.
• Current specifications list M5 × 20 mounting screws for hull thicknesses of approximately 12–17 mm; different fastener lengths may be required outside that range.
• Apply an appropriate marine bedding or sealing system, and tighten the frame evenly to avoid distortion. The frame installs with sealant or closed-cell PVC tape.

When to Replace a Portlight

Replace the complete portlight when the frame, glazing, hinge, or closing hardware is damaged beyond practical repair, or when leakage continues after the seal and installation surfaces have been inspected and serviced.

Manufacturer Schematic

Lewmar's official Hatch & Portlight Guide contains the Size 8 specifications and directs installers to the dedicated Size 8 cut-out drawing.

Also Available

• Lewmar — Size 0 Opening Stainless Steel Portlight — 239-393020262 — the smaller opening portlight in the same stainless series, with a different size and cut-out.
• BoatLIFE Life-Calk Marine Polysulfide Sealant & Bedding Compound – 10 oz. Cartridge, Clear — a marine bedding sealant for portlight and deck installations, sold separately.

Parts Desk Insights

• Best use case: Replacing a damaged Size 8 opening portlight, or fitting a new Lewmar Size 8 stainless-steel opening portlight where the elliptical cut-out already matches the dedicated Size 8 drawing.
• Most common customer mistake: Using the outside frame dimensions as the cut-out template. The Size 8 cut-out must be checked against Lewmar's dedicated drawing, not taken from the frame size.
• Sizing and fitment guidance: Confirm the vessel opening against the Size 8 drawing, check that the mounting surface is flat within approximately ±1 mm and between approximately 9 mm and 30 mm thick, and use the fastener length suited to the hull thickness before ordering.