I am pretty sure that the opening port size is a Lewmar #1, but I wanted to be sure. The only other possibility is the Lewmar size #0, but those seem too small. Any thoughts?

I have the old style (pre-1998?) twist lock portlights.

The old style Lewmar portlights (twist to lock) have two inherent design flaws. First, the twist locks actually penetrate the lexan cover. I have replaced the o-rings under the twist locks, tightened the twist locks, and taken numerous other measures, and they still drip.

The second flaw in the design is that the port gasket material is too narrow and too hard. (it only gets harder with age.) not only does it not compress well, but it's shape allows a puddle to form at the lower edge of the port, where it promply leaks through the twist locks. This is because angle of the cabin side is so shallow,

I have considered replacing the gasket, but the time I use to scrape the window frame clean enough to apply a new gasket, I could use to scrape the hull clean and put in a whole new portlight.

Also I am afraid that if I just replace the gasket, I will have not really addressed the two design flaws, and the ports will still leak.

If I could afford the Atlantic style protlights I would, but I am hoping that the new Lewmar standard portlights are at least better than the old.

I really just want ports that won't leak when it rains.. . .

Thanks, I feel better now.

Dave

I received my new Lewmar ports and they are a match for the ports on my 1995 MkII with the old style ports.

Just in case anyone else out there wants to replace their leaky Lewmars, the part number I ordered was Lewmar size #1 Standard ports (part number LEW393120200). They have white trim rings. Some might prefer ivory which is a different p/n.

I replaced my old style Lewmar opening ports with the new style today. The job was surprisingly easy. If anyone in the future has an interest in this project, I will be happy to give a full description, although I basically just followed the directions on the Lewmar website.

There is one watch out however. The metric M5-25mm screws that come with the opening ports are too long and will bottom out before the flange is tight. You will need to have on hand 12 M5-20mm screws per port.

Home Depot does not carry this size. Nor does Lowes. The local Ace hardware only carries 11. But if you are willing to go to enough hardware stores, you can finish the job in a day :)