AIr leak test.
That is our youtube page, use the search icon magnifying glass and search for "air leak"
Common spots for leaks are the daggerboard trunk, bailer seam and chine. Topside you might have water getting in through mast step, your can pour a cup of water in there and see if it disappears. Another common leak area is the seam on the older Sunfish with the metal trim.
Use low volume, low pressure air. Too much pressure can pop the seam or balloon the hull and detach the blocks. Soapy water in a spray bottle.
There are 33 plus designed holes in the Sunfish, plus the seam. Good luck!!
Kent and Audrey