Welcome to the ApneaScrap Lab blog.
The competition long fins are now complete and documented in the lab. The build page includes the layup, flex target, measured result, and the first in-water notes.
The first water trial was a good sign: the fins came out a bit soft and a little heavier than the training pair, but they still performed well in the water and landed on the target hydrodynamic resistance values.
Read the full build here: Competition Fins Project.
This note records the monofin layer stack derived from the Bluewater Freediving reference photo and cross-checked with the Predicting Flex technique.
I worked through the research on building a monofin leading edge and I am summarising the notes here. The aim is to replicate the low-drag, factory-style rail on a home-built monofin without special molds or cast urethanes.
After a season of pool and open-water sessions both of our documented rail-gluing approaches — Two-part Plastic to Carbon Adhesive and Marine Adhesive — started peeling right where the rails meet the foot pocket hardware. That joint sees the most peel stress when the blades flex, and the bond has been letting go in that exact spot.
The quickest fix has been to wick rubber-toughened cyanoacrylate (CA) under the lifted sections and clamp for a few minutes. That pinning keeps the rails in place for now, but it is still a patch layered on top of a bond that wants to fail.
The modular neck weight project page is now live. It covers the collar build, the add-on weight modules, and where the supporting techniques live in the lab guide.
If you need the build steps, you can read the full guide here: Neck Weight Project.