Lewmar

Lewmar Size 20 Low Profile Hatch Flange Base

SKU: 1000804 · UPC: 743683107078 · MPN: 39920030
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02 · Overview

Lewmar Size 20 Low Profile Hatch Flange Base — Product description

Discover the Sleek Performance of the Lewmar Size 20 Low Profile Hatch Flange Base

Upgrade your vessel's deck with this precision-engineered flange base designed for seamless integration into marine environments. Crafted for boat owners who demand reliability without compromising on style, this self-supporting component delivers exceptional ventilation and natural light while maintaining a streamlined, low-profile silhouette that hugs the deck closely.

Ideal for cabins, cockpits, or heads compartments, it features robust construction to withstand harsh saltwater exposure, UV rays, and everyday marine rigors. The smoke grey acrylic tint not only enhances privacy but also cuts glare for comfortable below-deck viewing, making it a favorite among sailors and powerboaters alike.

Precise Specifications for Perfect Fit

Every dimension has been meticulously optimized for straightforward replacement or new installations. Here's a breakdown of the core attributes:

Support System Lower Frame (in) Acrylic Colour Hatch Weight (lb) Acrylic Window Thickness (in)
Self Supporting 9/16 Smoke Grey 4.9 5/16

Overall Dimensions and Cut-Out Requirements

Ensure your deck prep matches these exact measurements for a watertight seal and effortless mounting.

Length X (in) Width Y (in) Height Z (in) Radii R (in) Cut-Out Length X1 (in) Cut-Out Width Y1 (in) Cut-Out Radii R1 (in)
10 11/16 16 7/16 1 2 7/8 7 15/16 13 11/16 1 11/16

Effortless Installation for Lasting Security

Mounting this flange base is straightforward, even for weekend warriors. Begin by confirming your deck surface is flat within a +/- 1mm tolerance—essential for preventing leaks and ensuring smooth operation.

  • Hinge Section: Secure with M6 (1/4") fasteners for rock-solid pivot points.
  • Lower Frame: Use 5mm countersunk (CSK) screws, No.10 UNC or 2 BA, to bed it flush against the gelcoat or fiberglass.
  • Pro Tip: Apply marine sealant around the perimeter before tightening to create an impenetrable barrier against water ingress. Torque fasteners evenly to avoid warping the frame.

With its lightweight 4.9 lb design, handling during install is a breeze, and the self-supporting mechanism means no additional stays or props cluttering your deck layout.

Why This Hatch Flange Base Stands Out on the Water

Beyond specs, this component shines in real-world use. The 5/16-inch thick smoke grey acrylic resists yellowing and crazing from prolonged sun exposure, preserving clarity for years. Its low 1-inch height minimizes windage and trip hazards, perfect for heel-prone sailboats or spacious power yachts.

Maintenance Made Simple

Keep it performing like new with basic care: Rinse with fresh water after saltwater dives, inspect seals seasonally, and lubricate hinges with marine grease. Avoid abrasive cleaners on the acrylic to maintain that crisp smoke grey hue— a quick wipe with microfiber and soapy water does wonders.

Boat enthusiasts rave about its quick-open action for superior airflow during hot anchors or overnight passages, blending form, function, and marine toughness seamlessly.

Frequently Asked Questions

What support system does the Lewmar Size 20 Low Profile Hatch Flange Base use?

It features a self-supporting system, eliminating the need for external stays and providing a clean deck appearance.

What is the weight of this hatch flange base?

The hatch weighs just 4.9 lb, making it lightweight and easy to handle during installation or maintenance.

What color is the acrylic window on this model?

The acrylic is in a smoke grey tint, which reduces interior glare while allowing ample natural light.

What are the cut-out dimensions for installing this hatch?

Cut-out requirements are 7 15/16 in length (X1), 13 11/16 in width (Y1), and 1 11/16 in radii (R1) for a precise fit.

What fasteners are recommended for mounting?

Use M6 (1/4\") fasteners at the hinge section and 5mm CSK screws (No.10 UNC or 2 BA) for the lower frame on a flat surface with +/- 1mm tolerance.

How thick is the acrylic window material?

The acrylic window measures 5/16 inch thick, offering durability against impacts and environmental stress.

Is this suitable for saltwater marine use?

Yes, its corrosion-resistant materials and robust design make it ideal for harsh saltwater conditions.

Support System Lower Frame (in) Acrylic Colour Hatch Weight (lb) Acrylic Window Thickness (in)
Self Supporting 9/16 Smoke Grey 4.9 5/16

Dimensions

Length X (in) Width Y (in) Height Z (in) Radii R (in) Cut-Out Length X1 (in) Cut-Out Width Y1 (in) Cut-Out Radii R1 (in)
10 11/16 16 7/16 1 2 7/8 7 15/16 13 11/16 1 11/16

Mounting Instructions
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.



"The Low Profile Hatch has soft styling and sleek looks, ideal for use on a powerboat. Smaller ventilation hatches are suitable for any deck location on sailboats, while the larger sizes can be used as foredeck hatches on smaller to mid size yachts."
SKU: NVN-1000804
MPN: 39920030
UPC: 743683107078
03 · The numbers

Technical specifications

BrandLewmar
ModelLewmar Size 20 Low Profile Hatch Flange Base
SKU / MFR#1000804

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04 · Before you buy

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05 · Customer voices

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