Fin Box Cho Hydrofoil

Print with supports. Use lots of walls and top layers.

3D printed fin boxes: are they strong enough? Since most of the forces are compressive layer adhesion should not affect the strength that much. The printed boxes strength (when printed solid) should be comparable to real ones. 

I recommend printing them in PETG  or ASA since it withstands uv and heat better than PLA. (Ive printed mine in PLA and they still work)

One version (Fin Box SL) has a sacrificial layer, so you can easily glass over the fin box without needing any masking tape. You can rough up all surfaces that will be in contact with glue with sandpaper for better adhesion. 

Designed with parameters, so you can easily change the length or tolerances in Fusion.

Pro tip: Drop a magnet in the fin box while it's printing to easily locate the fin box after it has been glassed over.