Lewmar Size 20 Ocean Series Hatch Flange Base
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Lewmar Size 20 Ocean Series Hatch Flange Base Product Description
Engineered for Superior Marine Performance
Discover the reliability of the Lewmar Size 20 Ocean Series Hatch Flange Base, a cornerstone for any seaworthy vessel. Crafted to withstand harsh marine environments, this flange base ensures a secure, watertight seal on deck hatches. Its robust construction supports the demands of ocean cruising, providing effortless ventilation and natural light below deck without compromising structural integrity.
Ideal for boat owners seeking a precise fit and long-lasting durability, this component integrates seamlessly with Lewmar's Ocean Series hatches. The smoke grey acrylic offers subtle UV protection and a sleek aesthetic that complements modern yacht designs.
Precision Specifications for Flawless Installation
Designed to mount on flat surfaces with a tight tolerance of +/- 1mm, installation is straightforward and professional-grade. Use M6 or 1/4" fasteners at the hinge section for rock-solid attachment, and 5mm CSK screws (No.10 UNC or 2 BA) for the lower frame to achieve a flush, streamlined finish.
| Lower Frame | Acrylic Colour | Hatch Weight (lb) | Acrylic Window Thickness (in) |
|---|---|---|---|
| 1" Flange | Smoke Grey | 6.04 | 3/8 |
Cut-Out and Overall Dimensions
These measurements guarantee a custom-like fit for your deck. Always double-check your cut-out against these specs to avoid rework.
| 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) | |
| 10 1/16 | 16 3/16 | 1 9/16 | 2 11/16 | 3/16 |
| 8 7/8 | 7 15/16 | 13 11/16 | 1 7/16 |
Pro Tips for Seamless Installation
Before fitting, ensure your deck surface is impeccably flat within the 1mm tolerance—sand or plane as needed for optimal performance. Apply marine-grade sealant around the flange perimeter to prevent leaks during heavy seas. Torque fasteners evenly to avoid warping, and test the hatch operation immediately after install. Lewmar's design minimizes hardware exposure, reducing snag risks and enhancing safety on deck.
- Prep Work: Clean the mounting area thoroughly; residue can compromise adhesion.
- Fastener Selection: Opt for stainless steel to match the corrosion-resistant build.
- Alignment: Use a template for cut-outs to maintain those precise radii and flats.
Why Boat Owners Trust Lewmar Ocean Series
Beyond specs, this flange base delivers real-world advantages. The 3/8-inch thick smoke grey acrylic resists yellowing and crazing from prolonged sun exposure, keeping your cabin bright for years. At just over 6 pounds, it won't overload your deck structure. Perfect for ventilation hatches in cabins, heads, or galleys, it promotes airflow to combat moisture buildup—a common issue in marine settings.
Compared to generic alternatives, Lewmar's engineering shines in extreme conditions: think gale-force winds or tropical downpours. It's a smart upgrade for older boats or a direct OEM replacement for peace of mind.
Longevity Through Simple Care
Keep it performing like new with routine checks. Rinse salt residue with fresh water after every voyage, and inspect seals annually. Lubricate hinges sparingly with marine grease to ensure smooth action. Avoid abrasive cleaners on the acrylic to preserve clarity.
Frequently Asked Questions
What surface tolerance is required for installing the Lewmar Size 20 Ocean Hatch Flange Base?
It fits flat surfaces with a maximum tolerance of +/- 1mm for a secure, leak-free mount.
What fasteners should I use for the hinge and lower frame?
Hinge section: M6 or 1/4". Lower frame: 5mm CSK screw (No.10 UNC or 2 BA).
What is the acrylic color and thickness on this hatch base?
Smoke grey acrylic with 3/8-inch thickness for durability and UV resistance.
How much does the complete hatch weigh?
Approximately 6.04 pounds, making it lightweight yet sturdy.
What are the key cut-out dimensions for deck preparation?
Cut-out length flat (X1): 7 15/16 in; width flat (Y1): 13 11/16 in; radii flat (R1): 1 7/16 in.
Is this flange base suitable for ocean-going boats?
Yes, part of the Lewmar Ocean Series, it's built for demanding marine conditions.
How do I maintain the acrylic window?
Rinse with fresh water regularly and use non-abrasive cleaners to prevent hazing.
- 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 | 6.04 | 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) |
| 10 1.2 | 16 3.16 | 1 9/16 | 2 11/16 | 3/16 | 8 7/8 | 7 15/16 | 13 11/16 | 1 7/16 |
"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."
Frequently Asked Questions (FAQ) About Lewmar Size 20 Ocean Series Hatch Flange Base
Who is the Lewmar?How to describe Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the highlights of Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the main features of Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the warranty policy for Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the type of the product?
What is the material of Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the size?
What is the dimensions of the product?
What is the cutout size of product?
What is the inside diameter of the product?
Who is the Lewmar?
How to describe Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the highlights of Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the main features of Lewmar Size 20 Ocean Series Hatch Flange Base?
- A Flange Base has a 1" flange that extends into the hatch opening.
- A Flat Base mounts to any flat surface, allowing installation over odd shaped openings.
- Ruggedly constructed with smoked gray acrylic lens and clear anodized-aluminum frame
- 10mm acrylic in sizes 10–40; 12mm acrylic in sizes 44–70
- Latches: Sizes 30 and larger have lockable internal and external handles for added security
- Hinges: Friction levers, hold position up to 95° angle
- Included Accessories: None (Trim and Screen Kits sold separately.)
- Warranty: Three years
What is the warranty policy for Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the type of the product?
What is the material of Lewmar Size 20 Ocean Series Hatch Flange Base?
What is the size?
What is the dimensions of the product?
What is the cutout size of product?
What is the inside diameter of the product?
Save $126 when you buy the Lewmar Size 20 Ocean Series Hatch Flange Base for only $444 from NVN Marine! Same day shipping before 3pm.
Lewmar Size 20 Ocean Series Hatch Flange Base Technical Specifications
| Type: | |
|---|---|
| Vendor: |
Lewmar |
| Weight: |
8.0 lb |
Lewmar Size 20 Ocean Series Hatch Flange Base User Reviews
Lewmar Size 20 Ocean Series Hatch Flange Base Shipping & Return
| Shipping Weight: |
8.0 lb |
|---|---|
| Box Sizes: |
1.00 (h) x 1.00 (w) x 1.00 (l) |
| Cubic Feet: |
1.0 |
| Returnable: |
Yes |
| USPS First Class: |
Yes |
| P65: |
Yes |
For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.



