Sailboat Hatches: Deck Hatches by Cut-Out Size, Profile and Brand
A hatch is a horizontal opening in the deck or coachroof that lets light and air into the cabin and, on the larger sizes, gives you a way in and out. Sailors search for hatches two ways: by brand and series (a Lewmar Low Profile, a Vetus Altus, a Goiot Opal) or by the cut-out they already have in the deck. This page covers the choice that applies to all of them: the cut-out size, the profile, and how the lid is held, locked and sealed. The brand ranges listed below each have their own collection.
Hatch Families and Where to Find Them
- Lewmar hatches: Low Profile (Size 00, 21.1 x 21.1 cm cut-out, up to Size 60, 50.7 x 50.7 cm, with round Size 18 and Size 22 versions), Medium Profile (Size 30 to Size 77, 69.9 x 69.9 cm), Ocean (Size 00, 25.5 x 25.5 cm, up to Size 70, 62.7 x 62.7 cm, in flange-base and flat-base versions), Flush (Size 10, 26 x 26 cm, up to 62.7 x 62.7 cm), Ultra Low Profile and Pilot hatches (Size 60 and Size 78, 72 x 77 cm). Lewmar spares are in a separate collection. Examples: Low Profile Size 60, Medium Profile Size 60 and Ocean Size 60 Flange Base.
- Vetus hatches: Altus (cut-outs from 26 x 26 cm to 62.7 x 62.7 cm, listed for design category A, opened from inside or outside, with a ventilation position and a watertight lock), Magnus (26 x 26 cm to 62.7 x 62.7 cm, CE classified A I, opens through 180 degrees), Planus (23 x 23 cm to 47.1 x 47.1 cm, CE classified A II, friction hinge for 180 degree opening, internal lock) and Flush (26 x 26, 44.2 x 44.2, 50.7 x 50.7 and 62.7 x 62.7 cm, recessed completely into the deck). The Altus, Magnus, Planus and Flush lids are listed with 10 mm acrylic. See the Altus 50.7 cm, Magnus 50.7 cm, Planus 42.4 cm and Flush 50.7 cm.
- Goiot hatches: Opal (Size T10, 26 x 26 cm, up to Size T70, 62.7 x 62.7 cm), Magic Flush (T10 to T70, in grey or black acrylic), Flush (T10 to T70), Cristal, Integra (including round sizes), and the Escape and Survival series. A Survival escape hatch hammer with support is listed alongside. Start with the Opal T60.
- Locker and access hatches in this collection: the Beckson 14 x 24 in Flush Hatch in white ASA with a UV-resistant finish; the Sea-Dog Triple Lock Rectangular Marine Hatch, 10 x 14 in, in white or black, with a triple-lock closure and gasket seal for below-deck storage; and the Whale TCL4 9 in Clear Locker Door, a clear lid for checking fuel levels, valves or safety gear without opening the locker.
Which Profile: Low, Medium, Ocean or Flush
- Low Profile: sits about 25 mm above the deck, according to Lewmar, the lowest of its three raised profiles.
- Medium Profile: about 32 mm above the deck. Lewmar describes it as sitting slightly higher than its low-profile range for more airflow and headroom, and as built for the repeated loads and exposure of offshore use.
- Ocean: about 40 to 43 mm above the deck, the highest of the three, available in flange-base and flat-base versions. Compare the two in the flat base vs flange base guide.
- Flush: Lewmar describes its flush hatches as sitting level with the deck, which needs a correctly shaped deck recess. Vetus says its Flush hatches suit new builds where the deck can be prepared for them, and that once fitted there is nothing to snag lines or feet.
- Ultra Low Profile: Lewmar lists the Ultra-Low Profile at about 10 mm above the deck on its product page, with a cut-out that aligns with its Low Profile, Medium Profile and Ocean installations.
How to Size a Hatch: Start from the Cut-Out
Hatch sizes are fit codes, not descriptions of the lid. Every listing carries its deck cut-out in the title, so measure the opening you have (or the opening you intend to cut) and match it. A few cut-outs recur across brands: 26 x 26 cm (Lewmar Size 10, Vetus 26 cm, Goiot T10), 32.7 x 45.7 cm (Lewmar Size 30, Vetus Altus, Goiot T30), 50.7 x 50.7 cm (Lewmar Size 60, Vetus Magnus and Flush, Goiot T60) and 62.7 x 62.7 cm (Lewmar Size 70, Vetus Altus and Magnus, Goiot T70). Treat that as a head start, not a guarantee: check dimensions and corner radius before fitting a hatch into another brand's opening, as Lewmar advises for its own hatches. On Lewmar Ocean hatches the flat-base cut-out is about 5 mm smaller each way than the flange-base one (Size 30: 32.7 x 45.7 cm flange base, 32.2 x 45.2 cm flat base). The guide to measuring a Lewmar hatch for replacement walks through it, and the hatch and portlight selection guide covers location, exposure and deck thickness.
Holding It Open, Screening It and Covering It
- Lifters and adjusters: the Hatch Lifters collection holds gas springs, hatch adjusters and a 12V Scandvik hatch lifter for holding a lid open. Vetus also lists stainless gas struts and hatch adjusters with its hatches.
- Mosquito screens: Vetus lists mosquito screens for its Planus hatches, and says an anodized aluminum counter flange and a mosquito screen are optional for the Planus.
- Covers: the Hatch Covers collection includes ATN ventilation caps for hatches up to 20 in and up to 24 in.
Who It Is For
Cruisers replacing crazed or leaking hatches on a boat with a known cut-out, refit projects adding ventilation or a second escape route, owners of production boats who need to match an existing opening, and builders choosing a flush hatch for a new deck. If you need a side opening rather than a deck opening, see Lewmar portlights or Vetus portlights.
Frequently Asked Questions
How do I find the right size for a replacement hatch?
Measure the deck cut-out, not the outside of the old frame, and match it to the cut-out printed in the listing title. Then check the corner radius and fastener pattern, because two hatches with the same cut-out can differ there. See how to measure a Lewmar hatch for replacement.
What is the difference between a Low Profile, Medium Profile and Ocean hatch?
Height and frame depth. Lewmar's hatch identifier gives about 25 mm above the deck for Low Profile, 32 mm for Medium Profile and 40 to 43 mm for Ocean. Ocean sits highest. The Lewmar hatch guide compares them.
What is a flush hatch and what does it need?
A flush hatch sits level with the deck. It needs a correctly shaped recess in the deck, so it suits new builds and refits where the deck can be prepared. Lewmar, Vetus and Goiot all list flush ranges.
Should I fit a hatch or a portlight?
A hatch is a horizontal opening for the deck or coachroof top; a portlight is set in the vertical side of the hull or coachroof. Most cruising boats use both, so air can cross the cabin. Our hatch, portlight and ventilator guide sets out what goes where.
Can I replace just the lid or seal on my hatch?
For Lewmar, yes: lids, seal kits, hinge kits and handle kits are sold separately in the Lewmar hatch spares collection. Match the exact series and size of your base so the new part seats and seals.