Lewmar Size 50 Low Profile Hatch Flange Base
Lewmar Size 50 Low Profile Hatch Flange Base — Product description
Discover the Sleek Performance of the Lewmar Size 50 Low Profile Hatch
Engineered for modern boats where style meets functionality, this Lewmar Size 50 Low Profile Hatch with flange base delivers a seamless integration into your deck. Its ultra-low 1-inch height minimizes wind resistance and creates a streamlined silhouette, perfect for sailboats, yachts, or cabin cruisers seeking that premium, factory-fresh look. The smoke grey acrylic window not only resists yellowing from UV exposure but also provides optimal light diffusion while maintaining privacy below deck.
Crafted with marine-grade durability in mind, the self-supporting design eliminates the need for additional gas struts in most applications, simplifying your setup while ensuring reliable operation in rough seas. At just 10.6 pounds, it's lightweight enough for easy handling during installation yet robust enough to withstand the rigors of coastal cruising or offshore adventures.
Key Features That Set It Apart
- Low Profile Aesthetics: Only 1 inch high, blending effortlessly with curved decks for a custom-built appearance.
- Smoke Grey Acrylic: 5/16-inch thick for superior impact resistance and clarity that lasts season after season.
- Self-Supporting Mechanism: Stays open securely without props, ideal for quick ventilation access.
- Flange Base Design: 9/16-inch lower frame ensures a watertight seal and straightforward mounting on flat surfaces.
- Generous Opening: Radiused corners prevent stress cracks, enhancing longevity in harsh marine environments.
Boat owners rave about how this hatch transforms cabin ventilation—fresh air flows freely without the bulk of traditional models, making it a favorite for liveaboards and weekend warriors alike.
Precise Dimensions for Perfect Fit
Measure twice for a flawless install. This hatch's footprint is thoughtfully proportioned to replace older models without extensive modifications.
| Dimension | Size (inches) |
|---|---|
| Overall Length (X) | 17 5/8 |
| Overall Width (Y) | 22 11/16 |
| Height (Z) | 1 |
| Radii (R) | 2 7/8 |
| Cut-Out Length (X1) | 14 13/16 |
| Cut-Out Width (Y1) | 19 15/16 |
| Cut-Out Radii (R1) | 1 11/16 |
Note: Overall dimensions include the flange base. Always verify your deck's flatness within +/- 1mm tolerance for optimal sealing.
Effortless Installation Guide
Installing this hatch is straightforward for DIY-savvy boaters. Prep your deck surface to ensure it's flat, then secure the hinge section with M6 (1/4-inch) fasteners. For the lower frame, opt for 5mm countersunk screws (No. 10 UNC or 2 BA equivalent) to achieve a clean, flush finish. Apply marine sealant around the cut-out for impenetrable waterproofing.
- Template and cut the opening precisely using the provided dimensions.
- Dry-fit the hatch to confirm alignment.
- Seal and fasten per specs—torque evenly to avoid warping.
- Test the self-supporting action and operation before launch.
Pro tip: In high-vibration areas, add lock washers to prevent loosening over time. Most installs take under two hours with basic tools.
Why Boaters Trust Lewmar for Ventilation Excellence
Beyond specs, this hatch shines in real-world use. The smoke grey tint reduces glare during midday sunbathing on deck, while the thick acrylic shrugs off accidental bumps from dock lines or crew traffic. Self-supporting means no fumbling with stays in a sudden squall—just flip it open for instant airflow. Pair it with companionways or dorades for superior cabin climate control, keeping mildew at bay even in humid tropics.
Regular upkeep is simple: Rinse with fresh water after saltwater exposure, and polish the acrylic annually with non-abrasive marine cleaners to maintain that crystal-clear view.
Frequently Asked Questions
What makes the Lewmar Size 50 Low Profile Hatch self-supporting?
The innovative design uses friction hinges that hold the hatch open securely without gas struts or props, perfect for reliable ventilation in various weather conditions.
What is the acrylic window color and thickness on this hatch?
It features smoke grey acrylic, 5/16 inch thick, offering UV protection, impact resistance, and a subtle tint for reduced glare.
How much does the Lewmar Size 50 Hatch weigh?
The complete hatch weighs 10.6 pounds, making it easy to handle solo during installation or maintenance.
What are the exact cut-out dimensions for installation?
Cut-out measures 14 13/16 inches long by 19 15/16 inches wide, with 1 11/16-inch radii for a precise, stress-free fit.
What fasteners should I use for mounting?
Use M6 (1/4-inch) at the hinge and 5mm CSK screws (No. 10 UNC or 2 BA) for the lower frame on a flat surface within +/- 1mm tolerance.
Is this hatch suitable for curved decks?
It's designed for flat surfaces with minimal tolerance variation. For slight curves, bedding compound can help achieve a watertight seal.
How do I maintain the smoke grey acrylic?
Rinse regularly with fresh water and use a mild plastic polish yearly to prevent hazing and preserve clarity.
| Support System | Lower Frame (in) | Acrylic Colour | Hatch Weight (lb) | Acrylic Window Thickness (in) |
| Self Supporting | 9/16 | Smoke Grey | 10.6 | 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) |
| 17 5/8 | 22 11/16 | 1 | 2 7/8 | 14 13/16 | 19 15/16 | 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.
"Lewmar Size 50 Low Profile Hatch Brand New Product # 39950030 The Lewmar Size 50 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-1002135
MPN: 39950030
UPC: 743683107184
Technical specifications
| Brand | Lewmar |
| Model | Lewmar Size 50 Low Profile Hatch Flange Base |
| SKU / MFR# | 1002135 |
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