It was designed for a standard aluminium tube (inner diameter 22mm or 7/8"). It was printed horizontally (on a side) with 70% infill.
Seems to be strong enough.
Might be scaled to any dimension.
Boathook_-_half_1.stl | 752.9KB | |
Boathook_-_half_2.stl | 753.6KB | |
Boathook_-_Part_1.stl | 1.4MB |