Nut plates or rivnuts might work google eitherThe thingies fixed to the cabin wall which accept the fixing bolts for the storm covers?????View attachment 124400
Perhaps the OP wants to just put them on & leave them on before ever leaving the pontoonI can't help thinking though that to fit covers like this in any heavy weather at sea would be extremely difficult. Fiddly screws and trying to line up the holes with one hand whilst hanging on would make it difficult. Lots of spare screws needed. Obviously better to fit them before the weather arrives but like putting a reef in, we don't always get it right with our predictive actions.
I like that suggestion, as having sharp-ended bolts sticking out is a menace. Another version I saw on a Fisher was to have a rail on either side to slide the cover into - a very quick way to employ if things started to get rough.Just a thought re a slightly different way of arranging storm covers - I remember seeing something like this on a yacht some years ago.
Rather than fasteners as shown in the photo, small U-Bolts were used, with one in each corner of a rectangular shaped storm cover.
The size was such that if a slot was cut in the storm cover for the U-Bolt, then a carabiner hook (or similar - even a shackle could be used) was put through the 'U' to secure it in place.
They would not be 'watertight' covers - they just help to stop the window underneath from fracturing if a big sea hits it.
The cover panels shown in the photo above would not necessarily be watertight either, unless a lot of sealant was employed underneath them.
This. Just good DIY work.It's a small piece of metal with 3 holes in it, the middle one tapped.
You get them from a metal scrap bin and cut, file, drill, tap.
Or look to 're-purpose' some stainless component.