I have an “ocean kayak” which means it has holes for the water waves deposit into the kayak to drain out of.

But I don't use it in the sea, I use it in the local canal, and I want to minimise the canal water coming into the kayak through these holes.

I had no idea what a suitable plug would be, so I got the calipers out and made one to suit.

I used threads.scad to add a gentle ribbing to the outside, which is then wrapped in Self-amalgamating tape to form a waterproof and grippy outside to the plug (the ribbing helps the tape have something to grip onto when shoved into the hole. Or so my theory goes.)

Alternatively, you could print it slightly larger in TPU maybe?

Printing

I used filamentive recycled PLA, and made some choices to try and keep it somewhat watertight.

The “handle” didn't handle the overhangs well but it is functional so 🤷

Print time was around 1 hour 15 per plug on my Anycubic Vyper.

• 3 wall loops (could do more?)
• 4 top and bottom layers (could do more?)
• 220 (on the hot end of hot end temperatures to help fusing of layers)
• 0.3mm layer height (it's not got a lot of detail)
• 10% rectilinear/line infill (it's probably not that important given the number of walls)

After, wrap it in two or three layers of tape (depending on how thin you pull it, can always add more if needed) and shove it into the kayak holes!

Adjusting  / customising / parametric-ing

The scad file is included with as many unused functions removed  from the threads library as I could be bothered to work out.

Variables allow you to adjust the diameter and height of the plug, the “tolerance” (aka how much tape you'll add / should probably be called “hole size”), and the handle size.