30-second answer
Add the complete operating package before comparing a tender with a davit rating.
Best forDavit-mounted tenders and buyers comparing different hull materials
Watch outDo not use brochure hull weight as the lifted load
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Hull Weight vs Ready-to-Use Dinghy Weight
Every manufacturer publishes a hull weight, and almost none of them publish a ready-to-use weight. The gap between the two is routinely 60–100 kg, which is more than enough to take a tender from comfortably within your davit rating to dangerously over it.
A buyer deciding between a 2.9 m aluminium RIB and a premium fibreglass RIB needs the total davit load, not the boat-only weight. Two boats that look 20 kg apart on paper can be 45 kg apart in the water.
How to Calculate Ready-to-Use Dinghy Weight
Add every item that lives in or on the boat when it hangs:
Ready-to-use weight =
Hull
+ Outboard
+ Fuel (full tank)
+ Battery
+ Anchor
+ Rode
+ Safety gear
+ Console (if fitted)
+ Launching wheels
+ Electronics
+ Lifting gear / bridle
Ready-to-Use Weight Calculation Example
Take a nominal 3 m aluminium RIB with a published hull weight of 48 kg. Fit a 15 hp four-stroke at around 45 kg, a 12 litre tank at around 12 kg full, launching wheels at around 6 kg, an anchor and rode at around 8 kg, safety gear and a bridle at around 6 kg.
Hull weight: 48 kg. Ready-to-use weight: roughly 125 kg. If your davits are rated to 120 kg, the brochure said yes and the boat says no.
Davit Safety Margins for Total Dinghy Weight
- Get the davit or lifting-point rating in writing before you shortlist.
- Weigh the outboard you actually intend to buy, not the lightest one in the range.
- Decide early whether fuel lives in the tender or gets carried separately — it is often 10–15 kg of flexibility.
- If you are within 10% of the rating, choose the smaller boat. Davit failures happen at sea, in a swell, at the worst possible moment.
How this guide was made
Written and reviewed by Gabriel Machuret. BuyDinghy compares published manufacturer and Australian distributor material, labels missing specifications instead of estimating them, and separates editorial judgement from verified facts. Read the methodology or report a correction.