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Lewmar opening and fixed portlights in the Standard, Atlantic, Flush Mitre and Stainless Steel series, matched by cut-out size, plus flyscreens, trims and Eclipse roller shades. Click here to read more.

Lewmar Portlights: Standard, Atlantic, Flush Mitre and Stainless Steel, Sized by Cut-Out

A portlight is the opening or fixed window set into a cabin side or coachroof, and the one measurement that decides what you can fit is the cut-out in the cabin wall, not the overall frame. Lewmar portlight titles list the cut-out, so you can compare your existing hole directly against the size. This collection covers the Lewmar Standard, Atlantic, Flush Mitre and Stainless Steel portlight series, plus the flyscreens, interior trims, screws and Eclipse roller shades that go with them.

Lewmar Portlight Series in This Collection
  • Standard series: sizes 0, 1, 2, 3, 4, 5 and 7RE, plus Size 1 Round End and the long Size 4L and 4R, in several acrylic tints with silver frames and white or ivory trim. Cut-outs run from 15.6 x 30.3 cm (Size 0) up to 17.5 x 68.8 cm (Size 4L and 4R). The listing describes a clamp fit: the cabin side is held between the inner and outer frames with screws, set in sealant or closed-cell PVC tape, with white ABS trim inside. Start with the Size 1 or the Size 3.
  • Atlantic series: sizes 10, 30, 32, 40 and 60, with an anodised extruded aluminium frame, quick-action handles that apply even pressure on the seal, friction hinges instead of stays or straps, and an outer frame shaped so water drains away on an angled coachroof side. Cut-outs run from 15.4 x 28.4 cm (Size 10) to 18 x 58 cm (Size 60). Each size comes in thick-valance and thin-valance versions, and the listing says all sizes except 10, 30 and 32 (thin valance) and 30 (thick valance) are made to order. See the Size 40, thick valance or the Size 60, thin valance.
  • Flush Mitre series: sizes 0, 1, 3, 4 and 5 in black, grey or dark grey acrylic with a silver or grey frame. Lewmar developed it from the Standard portlight to keep the acrylic almost flush with the mounting surface, using thicker acrylic and a flat outer frame powder-coated black to blend with the lens. The cut-outs match the Standard sizes of the same number. See the Size 1 and the Size 4.
  • Stainless Steel series: sizes 0, 1, 1-RE, 7-RE and 8, in opening and fixed versions, with polished stainless outer frames and chrome or white plastic trim inside. The handles and hinges leave the lens clear of obstructions. Compare the Size 0 opening with the Size 8 fixed.
  • Eclipse roller shades: blackout shades with flyscreen mesh and an adjustable tensioning mechanism, in portlight sizes 0, 1, 2/3/5, 4, 10, 20, 30 and 50, with trim kits for sizes 10, 20 and 30. Browse the full Eclipse series.
  • Flyscreens, trims and screws: clip flyscreens for Standard and Atlantic sizes, stainless interior trims, and M5 screws in 12, 16, 30 and 35 mm lengths, in packs of 100, for example the M5 x 12 mm screws. More parts are in Lewmar Portlights - Accessories and Lewmar Portlights - Spares.
Cut-Out Sizes by Series
  • Standard and Flush Mitre: Size 0 is 15.6 x 30.3 cm, Size 1 is 17.1 x 34.7 cm, Size 3 is 17.1 x 42.9 cm, Size 5 is 24.4 x 42.9 cm and Size 4 is 17.1 x 62.6 cm.
  • Standard only: Size 2 is 15.6 x 40.5 cm, Size 7RE is 17.1 x 40.5 cm and Size 4L and 4R are 17.5 x 68.8 cm.
  • Atlantic: Size 10 is 15.4 x 28.4 cm, Size 30 is 18 x 38 cm, Size 32 is 17.8 x 38.1 cm, Size 40 is 18 x 46 cm and Size 60 is 18 x 58 cm.
  • Stainless Steel: Sizes 0, 1 and 7-RE use the same cut-out as the Standard portlight of that size; Size 8 is 17.6 x 43.2 cm.

Figures are the cut-outs in the product titles.

How to Choose
  • Start with the existing hole. Measure the cut-out in the cabin side and match it to a size above. Replacing like for like is the simplest route; moving to another series usually means a different cut-out. Our portlight sizing guide walks through it.
  • Standard or Atlantic: Standard is the clamp-fit portlight with plastic trim; Atlantic has the anodised aluminium frame, the drainage lip and the friction hinges. Our Lewmar portlight guide compares the raised Standard and Atlantic styles with the Flush Mitre.
  • Flush Mitre when you want the lens almost level with the cabin side. Our guide notes it needs a more precise cut-out, and the listing says the flyscreen is not supplied as standard.
  • Stainless Steel for a polished stainless frame; choose opening for airflow or fixed for light only.
  • Hull thickness: opening angle is restricted on thick hulls. The Standard listing gives 165 degrees at 21 mm hull thickness; an Atlantic Size 30 listing gives 115 degrees at 24 mm. Check the valance type against your hull thickness before ordering.
Fitting Notes
  • The Standard listing states portlights are supplied with 12 M5 x 25 screws for a hull thickness of 17 to 25 mm; sides outside that range need other screws.
  • The Atlantic listing asks for a flat mounting surface within +/- 1 mm.
  • The Standard listing says a flyscreen is supplied except on the 4L and 4R; the Atlantic listing says its nylon flyscreen clips onto the outer frame and can stay in place with the window closed.
  • Lewmar portlights are supplied from the manufacturer and the Atlantic listing says most sizes are made to order, so confirm size and colour on the product page and plan the refit around the lead time.
Who It's For

Owners replacing a worn portlight, refit projects renewing cabin sides, and anyone matching a Lewmar series to a cut-out they already have. Looking for hatches instead? Browse Lewmar Hatches, or read our guide on hatch, portlight or ventilator.

Frequently Asked Questions

How do I find the right Lewmar portlight size?
Measure the cut-out in the cabin side, not the visible glass or the overall frame. The size is tied to the cut-out, so a Standard Size 1 is 17.1 x 34.7 cm and an Atlantic Size 40 is 18 x 46 cm. Match yours to the list above; our sizing guide covers measuring and templates.

What is the difference between Standard and Atlantic portlights?
Both are Lewmar opening portlights. The Standard is clamped between inner and outer frames with ABS trim; the Atlantic has an anodised extruded aluminium frame, quick-action handles, friction hinges and an outer frame that drains water away. Sizes and cut-outs differ, so check the list before swapping one for the other.

Are there fixed Lewmar portlights?
Yes, in the Stainless Steel series, which lists both opening and fixed versions, for example the Size 1 fixed and the Size 8 fixed. A fixed unit gives light only, with no hinge or handle to maintain.

Does a Lewmar portlight come with a flyscreen?
The Standard listing says it is supplied with a flyscreen except on the 4L and 4R, and the Atlantic listing says its flyscreen is supplied as standard. The Flush Mitre listing says the flyscreen is not supplied as standard. Spare clip flyscreens are listed by size, such as the Atlantic Size 40.

Can I add a shade to a Lewmar portlight?
Yes. The Eclipse roller shade uses 100% blackout material that is UV stable and water repellent, with flyscreen mesh for airflow, and is sold by portlight size, for example the Size 30. Pick the shade size that matches your portlight size on the product page.