Lewmar Portlight Range Identification

Updated: Dec 30, 2020

With hatches done, it's time to turn our attention to the various Lewmar portlight models.

In terms of design the catalogue variants are:


  • Old Standard (obsolete 1982-1998)

  • New Standard - Mk 1 (obsolete 1997- June 2000)

  • New Standard - Mk 2 (2000-2007)

  • New Standard - Mk 2b (2007-)

  • New Standard - Mk 3 (2012-)

  • Atlantic (1994-)

  • Ocean (obsolete 1990 - 2007)

In addition, there are other models which are new enough not to require refurbishment yet and so are not discussed here:

  • Stainless (2003-)

  • Flush Bent Portlight (2008-)

  • Flush Mitre Portlight (2009-)

  • Concept 3 (2009-)

In addition Lewmar produced ranges of custom portlights (opening) and fixedlights (fixed) for yacht builders in craft specific sizes. For Hallberg Rassy, Lewmar also produced a 'version' of the Atlantic model with slightly different fixtures called ASTAR.


Some craft may have a mix of models including what appear to be Atlantic but whose acrylics are simply marked 'Portlight'.


Trim pieces (the white/cream mouldings fitted inside your boat) are normally the first 'spare' to go out of stock once a portlight becomes obsolete and with UV exposure become brittle (and discoloured) so are prone to damage. So please be careful if/when removing.


Note that all Lewmar units (hatches and windows) manufactured from 1997 will have the unit code hot stamped onto the acrylic, details of which are in another Blog post.


Lastly, before looking at the ranges, we did a previous Blog article which overlaps, but which includes important information relating to the types of frame joint as an additional means of identifying the range.


Old Standard (OS)

Available in fixed and opener format in catalogue sizes 0, 1, 2, 3, 4, 4L, 4R, 5, 6, 7RE (RE for soft rectangular corners vs radiused). We seldom see sizes 3, 5, 6, 7RE but often see sizes 0, 1, 2 and 4L/R. Sizes 4L/R are asymmetric with a slightly pointed end. They feature hinge/handle mouldings which are bolted through the 8mm acrylic.


We can supply replacement acrylics for DIY fitment (see previous blog post for how) and can also fit a new closing seal to the outer frame (this is not as straight forward as might first appear as the seal is also sealed with silicone which needs to be cleaned out prior to refitting and is a workshop job). The outer frame features two sections joined at each end with alloy fishplates and sealed with a rubber insert moulding. These mouldings fail and are known to lead to leakage under the handles. We replace these with sealant which provides a longer lasting solution.


New Standard (NS)


These have the same cut-out as OS and are thus direct replacements for the same size code in either fixed or opener format. The opening NS has a number of versions, the earlier of which are NOT interchangeable. The NS openers are easily identified by having bonded (ie glued, rather than bolted) hinge/latch fixings (termed 'mouldings' by Lewmar). Otherwise similar with a moving acrylic pane which is held against a closing seal mounted on the inside of the outer frame. NS opener acrylics where available, can only currently be sourced from Lewmar (through us) as no one outside Lewmar is authorised to bond mouldings. We are working with Lewmar on this, but for now that's the situation. As you will see this has significant ramifications for some owners with opening portlights.


All of what follows relates to the opening versions. Fixed NS portlights can all be refurbished without any problem; we just replace the acrylic and seal.

NS Mk 1 (1997- June 2000) have hinge/latch mounts which are pressed into position on the outer frame.

This differs fundamentally from subsequent (Mk 2+) versions where the mounts are attached to the outer frame with machine screws.


Mk 1 mouldings are not compatible with Mk 2+ and this, coupled with the fact that Lewmar have no remaining Mk1 mouldings means that NO new acrylic replacements are available (unless new/old stock at a builder). So, if your boat has Mk 1 NS portlights in catalogue sizes (0-5) your only option is to replace the whole unit with a Mk 2+ equivalent which we can source from Lewmar.

NS Mk2+ (2000-) have screwed mounts as mentioned/shown above. There was a change in 2007 (see image below) at which point the hinge pin diameter was increased from M4 to M5 and the handle/latch was lengthened, but any Mk 2 acrylic kit will include parts for both. These later over-cam versions also have a slightly longer latch type handle, but these changes don't impact spares availability - you just get the current version.

From January 2012 Lewmar also listed a version with a twist type rather than over-cam handle as shown to the right. Though the handles were bolted through the acrylic (like the original OS) the hinge mouldings remain bonded (so unsuitable for non-Lewmar replacement).


Note that if you have custom NS openers, spares are generally not available from Lewmar, except by special order. This is discussed elsewhere as it's too large an issue for here....


Atlantic (ATL)

Available as a fixed or opening portlight. Heavier duty than the OS/NS, the acrylics have a bevelled edge held by clips as well as sealant/glazing tape. Sizing is different to OS/NS and in catalogue sizes includes 10, 30, 32, 40, 41, 43, 52, 60 and 64. We can refurbish all fixed and opening variants of the Atlantic and the Hallberg Rassy versions (branded ASTAR).


The Atlantic (ASTAR) opener is characterised by having the acrylic mounted in a moving aluminium frame. Hinge and latch fixings are attached to both the moving and outer frame with countersunk machine screws with a 4mm Hex head. These are often fitted with loctite so a heat gun aids removal. On the Atlantic the latch has a chromed appearance where as (ironically) the HR ASTAR version have grey plastic finish.


As with OS/NS, the closing seal is both mounted and sealed (with silicone) within a channel in the outer frame. This channel is complex and challenging to clean on the bench, but virtually impossible in situ. As with OS, we can replace just the acrylic or also change the closing seal, but if both will need the whole unit sent in.

Ocean (OCP)

The Ocean was only available as an opener and in one size. Like the ATL it features an acrylic pane mounted in a moving aluminium frame which clamps against a closing seal mounted on the inside of the outer frame. Designed for ocean use as a 'more' watertight version of the Atlantic. These can (and have) been refurbished and new closing seal is available, but as above this is a workshop task. Note the slightly different latch moulding vs NS/ATL.





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