Lewmar

Lewmar Size 30 Ocean Series Hatch Flange Base

SKU: 1000796 · UPC: 743683101885 · MPN: 39630070
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02 · Overview

Lewmar Size 30 Ocean Series Hatch Flange Base — Product description

Upgrade your vessel's deck with the Lewmar Size 30 Ocean Series Hatch Flange Base, a cornerstone of durable marine hardware designed for serious offshore conditions. This flange base (model 39630070) pairs seamlessly with Lewmar's renowned Ocean hatches, delivering a sleek, low-profile fit that enhances ventilation while shrugging off harsh saltwater exposure. Boat owners swear by its engineering—built tough with corrosion-resistant materials to handle relentless UV rays, pounding waves, and temperature swings without cracking under pressure.

Key Features That Stand Out on the Water

  • Precision Fit for Seamless Installation: Mounts effortlessly to flat surfaces with a tolerance of just +/- 1mm, ensuring a watertight seal that prevents leaks even in rough seas.
  • Robust Fastening Options: Hinge section secured with M6 or 1/4" fasteners; lower frame uses 5mm CSK screws, No.10 UNC, or 2 BA for rock-solid hold.
  • Smoke Grey Acrylic Excellence: Tinted for glare reduction and privacy, with a hefty 3/8-inch thickness that resists hazing and yellowing over years of sun exposure.
  • Lightweight Yet Sturdy: At only 9.09 lbs, it won't weigh down your boat, balancing strength with easy handling during installs or upgrades.
  • 1-Inch Flange Design: Provides ample overlap for superior bedding and sealing, ideal for cabin tops, foredecks, or heads compartments.

What sets this apart from generic deck hatches? Lewmar's Ocean Series draws from decades of racing and cruising feedback, incorporating quick-action gearing for smooth operation and stays that lock securely at multiple angles. It's not just a hatch base—it's your gateway to reliable airflow that keeps cabins fresh without compromising structural integrity.

Detailed Specifications at a Glance

Attribute Detail
Lower Frame 1" Flange
Acrylic Colour Smoke Grey
Hatch Weight 9.09 lb
Acrylic Window Thickness 3/8 in

Precise Dimensions for Perfect Cut-Outs

Getting the cut-out right is crucial to avoid headaches during refits. Here's the blueprint:

Dimension Imperial (in)
Length X 15 3/8
Width Y 20 1/2
Height Z 1 9/16
Radii R 2 15/16
Hinge Length HX 3/16
Hinge Width HY 13 3/16
Cut-Out Length Flat X1 12 7/8
Cut-Out Width Flat Y1 18
Cut-Out Radii Flat R1 1 11/16

Installation Insights from a Marine Vet

I've seen too many botched hatch installs lead to cabin floods. Start by double-checking your deck's flatness—sand high spots if needed. Bed the flange with a marine sealant like polyurethane for flexibility. Torque fasteners evenly to spec, and test the hatch cycle before final tightening. Pro tip: Pair with Lewmar's Ocean lid and quick-action handle for buttery-smooth venting that adjusts from 10° to 90° effortlessly. Maintenance is a breeze—just rinse with fresh water after every voyage and inspect seals annually to keep it leak-free for a decade or more.

Why Boaters Choose Lewmar Ocean for the Long Haul

In the world of marine hatches, Lewmar Size 30 shines for its balance of form and function. Unlike bulkier alternatives, its slim profile reduces windage and snag risks on deck. The smoke grey tint cuts cockpit glare during those long night watches, and the beefy acrylic laughs off impacts from errant fenders. Whether retrofitting a classic sailboat or outfitting a modern cruiser, this flange base delivers the ventilation punch you need without the drama.

Frequently Asked Questions

What surfaces can the Lewmar Size 30 Ocean Hatch Flange Base mount to?

It fits flat deck surfaces with up to +/- 1mm tolerance, making it versatile for fiberglass, cored decks, or metal topsides when properly prepped.

What fasteners should I use for installation?

Use M6 or 1/4" for the hinge, and 5mm CSK, No.10 UNC, or 2 BA screws for the lower frame. Always back them with through-bolts or washers for maximum strength.

Is the acrylic tinted, and how durable is it?

Yes, smoke grey tint reduces UV penetration and glare. At 3/8-inch thick, it's impact-resistant and maintains clarity far longer than thinner competitors.

What's the approximate weight of this hatch base?

The complete Size 30 assembly weighs about 9.09 lbs, keeping your boat's center of gravity low and handling straightforward.

How do I measure for the cut-out?

Use 12 7/8" length x 18" width with 1 11/16" radii for flats. Template it first to ensure precision and avoid enlarging later.

Can this handle offshore sailing?

Absolutely—Lewmar Ocean Series is battle-tested for bluewater passages, with seals and hardware proven in extreme conditions.

What's the flange size on this model?

It features a 1-inch flange, providing excellent overlap for bedding and a secure, drip-free edge.
  • Fit to a flat surface with a maximum tolerance of +/- 1mm.
  • Fastening size at hinge section use (M6 / 1/4").
  • Fastening size for lower frame use 5mm CSK screw No.10 UNC 2 BA.
Lower Frame (in) Acrylic Colour Hatch Weight (lb) Acrylic Window Thickness (in)
1" Flange Smoke Grey 9.09 3/8

Dimensions

Length X (in) Width Y (in) Height Z (in) Radii R (in) Hinge Length HX (in) Hinge Width HY (in) Cut-Out Length Flat X1 (in) Cut-Out Width Flat Y1 (in) Cut-Out Radii Flat R1 (in)
15 3/8 20 1/2 1 9/16 2 15/16 3/16 13 3/16 12 7/8 18 1 11/16


"LewmarFit to a flat surface with a maximum tolerance of +\/- 1mm. Fastening size at hinge section use (M6 \/ 1\/4\"). Fastening size for lower frame use 5mm CSK screw No."
SKU: NVN-1000796
MPN: 39630070
UPC: 743683101885
03 · The numbers

Technical specifications

BrandLewmar
ModelLewmar Size 30 Ocean Series Hatch Flange Base
SKU / MFR#1000796

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04 · Before you buy

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05 · Customer voices

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