Vertebrae for the anchor rode
A chain of snap-on links that clips around the rode where it runs over the bow roller. It lets the rope bend the way it is meant to and stops the bend that goes the other way.
The problem
An anchor rode dies at the bow roller, and a pot bridle dies where it leaves the frame. It dies of two things at once: abrasion, and being bent too sharply under load. Chafe guards and sleeves only cover one half of that. They give a surface that wears instead of the rope, but do nothing about how tightly the rope is allowed to bend. Most of them cannot be fitted to a rope that is already spliced either, not without cutting the splice off.
The fix
The principle comes from subsea. A bend restrictor down there is a chain of links, a ball on one end and a socket on the other, and once the lip of the socket meets the next link the chain simply cannot bend any tighter. The difference here is that a subsea restrictor is the same all the way round, because a riser can be pulled from any heading. Over a bow roller that is wrong. The rode is supposed to bend freely one way and be stopped the other, because it is the reverse bend — the boat sheering off and the rode slapping back across the stemhead — that kills rope. So the socket lip is cut away on one side and left standing on the other, and the links go on with the free direction facing the roller. The other way it stops at around eight rope diameters.
Each link is a C-shell with a printed catch, so the whole chain clips onto a rode that is already spliced. Material is ASA or PA-CF; PETG will not hold up in sun over time. Links print one at a time, with the ball and socket faces oriented so the layers do not stair-step them, and the catch needs about 0.15 mm of dimensional control. That is within reach on a printer that has been dialled in, but it has to be measured rather than assumed. Sizes follow the rope: 10, 12, 14 and 16 mm. This is a wearing part. The plastic is there to be ground away instead of the rope, which means it gets ground away. How long a set lasts I will not know until it has been out for a season, and either way it does not make a worn rope safe again.
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.