Fender clamp for the rail
A clamp with a soft liner that keeps the fender line where you put it, and releases with one hand.
The problem
The fender slides along the rail just as you come alongside, and the knot you tied last year has seized solid. There are always two hands too few in that moment.
The fix
The clamp is drawn to one tube diameter — 25 or 30 mm — with a TPU liner that grips without marking the rail, and pulls up on an A4 stainless bolt. The line locks into a toothed wedge, and the teeth are printed lying down. Printed standing up, they shear along a layer the first time the line snatches.
The clamp body is ASA. PETG would last a season or two but loses its surface after enough sun and salt spray. The test is a wet fender and a bit of sea: if the line has not moved after an hour in a swell, it holds. This is a hanger for fair weather and short stops, not something meant to hold a boat in a blow.
More ideas
A hook guard that actually stays on
A soft TPU clip that snaps over treble hooks and jigs so they stop catching nets, clothing and fingers.
A rod holder that fits your rail
A parametric holder printed for the exact tube diameter your boat has — not a standard no boat actually follows.
Gear tags for nets and pots that last
Name, phone number and registration embossed into the tag itself — not written in marker that vanishes in three weeks.