3D-Printed Upgrades for Your Dinghy and Tender

Ask any cruiser which boat breaks more gear per season — the mothership or the tender — and the answer is almost always the tender. Dinghies live a hard life: dragged up beaches, hoisted on davits, left inflated in the sun, towed through chop, and loaded with jerry cans and groceries. And most of what breaks on them is exactly the kind of part a desktop 3D printer handles well: small plastic fittings, clips, collars, plugs and pads that chandleries either don't stock or sell as part of an overpriced "kit".

This guide walks through the tender upgrades and repairs that make the most sense to print, which materials to use for each, and where the limits are.

Why tenders are the perfect 3D-printing candidate

Three reasons. First, almost everything on a dinghy is small — well within the build volume of any FDM printer. Second, most dinghy hardware is non-structural in the safety sense: if an oar collar or a fuel line clip fails, you're inconvenienced, not endangered. Third, dinghy parts are notorious for being model-specific and discontinued. The plastic rowlock insert for a fifteen-year-old inflatable is often simply unobtainable — unless you print it.

Oar collars and rowlock inserts

Oar collars (the sleeve that stops the oar sliding through the rowlock) and the plastic bushings inside rowlocks are among the first things to wear out. Both are ideal prints:

• Collars: print in TPU (95A) so they grip the oar shaft without cracking. A parametric collar sized to your exact shaft diameter beats any "universal" rubber part that slips.
• Rowlock bushings: PETG works, but nylon is better if you row a lot — it's self-lubricating and handles the constant oscillation without squeaking.

Measure the shaft and socket with calipers before ordering or generating a file — our guide on how to measure for a perfect printed fit applies just as well to oars as to hoses.

Outboard and transom hardware

The outboard end of the tender is a goldmine of printable parts:

• Clamp pads: the plastic pads on outboard clamp screws crack and fall off. A printed replacement in PETG with 50%+ infill outlasts the original — and you can print a spare while you're at it.
• Fuel line clips: simple U-clips that keep the fuel hose off the floor and away from chafe. Print several; they cost cents.
• Tiller extensions and throttle grips: a printed sleeve over a worn throttle grip, or a clamp-on tiller extension bracket, transforms an old outboard.
• Kill-switch lanyard clips: easy to lose, easy to print.

Drain plugs and bungs

Drain plugs are printable — with caveats. A threaded transom plug in PETG with a TPU gasket seals fine for a dinghy that's hauled regularly. Print threads oversized-tapped or use a parametric file with the thread clearance already tuned for FDM; a plug that needs force to thread in will eventually crack. For anything that stays in the water unattended, carry the original as primary and treat the print as your spare. Never rely on a printed plug as the only thing between the sea and a boat left on a mooring.

Chafe guards, davit pads and towing hardware

Everything that rubs on an inflatable eventually wears a hole in it. Flexible TPU is the answer:

• Chafe guards where the painter crosses the bow tube or a davit strap bears on fabric.
• Davit spacers and pads that stop stainless hooks from grinding on the transom.
• Painter line clips to keep the tow line from dragging in the water underway.

We covered flexible filament in depth in TPU on board: chafe guards, gaskets and bumpers — the same settings apply here. For rigid clips and organizers that keep lines tidy, browse the deck & rigging collection.

Pump adapters and inflation fittings

Inflatable owners know the pain: every pump has a different nozzle, every valve a different socket. A printed adapter that mates your pump hose to your specific valve (Halkey-Roberts, Leafield, Bravo) is a ten-gram print that ends the wrestling match. PETG is fine here — the pressures involved are low (most tubes run 0.2–0.25 bar). Sizing an adapter is the same job as sizing any hose fitting; the plumbing & pumps collection has parametric fittings you can size to odd hose diameters directly.

Material quick reference

For the full reasoning behind these picks, see our materials guide for boat parts.

A note on safety

3D-printed parts are not certified marine equipment. On a tender that's usually fine — most of these parts are convenience hardware — but apply judgment: don't print the lifting eyes your dinghy hangs from on davits, don't trust a printed part as the sole drain plug on an unattended boat, and verify material suitability before using any printed part in a fuel system or other critical application. When in doubt, the print is the spare, not the primary.

Start with the free files

Several of the parts above — clips, hooks and organizers — have free parametric versions in our free collection. Enter your measurements, download the STL sized to your gear, and print. If your dinghy needs something more specific, every parametric file in the full catalog generates to your exact dimensions — because no two tenders, oars or valves are ever quite the same. Questions about a specific part? Write to info@marinelab3d.com.