Rod cradles for the car and the boat
Cradles with a soft liner that hold the rod still in transport, clamped to a roof bar or to the rail.
The problem
Rod tips rarely break on the water. They break in the car, in a door, or under a tarpaulin. A rod lying loose rolls, and then the reel seat grinds against the same edge for the whole trip.
The fix
The cradle is a V with a TPU liner, and the band that closes around the bar pulls up on an A4 stainless bolt. No brass inserts: brass and stainless in salt water make a galvanic pair, and the insert is the first thing to go. The clamps are drawn for 22, 25 and 30 mm tube with 0.4 mm of clearance, so they can be tightened without splitting.
The band is printed lying down so the load runs in the plane of the layers. A printed part holds roughly half as much across the layers as along them, and a band printed standing up parts exactly where you tighten it. The prototype has done gravel roads and a winter of sub-zero mornings without cracking, though the liner is an annual replacement — the TPU polishes smooth and stops holding.
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.