Fenders—also called bumpers or fenders—are essential for every boat. They protect the hull from scratches, dents, and damage when mooring or docking. But which fender is best suited for your boat, and how many do you actually need? This guide explains it clearly.
Why are fenders important?
A fender is an inflatable buffer that protects your boat during maneuvers in the harbor, when mooring, or when moored alongside other vessels. Without fenders, your boat is at risk of damage that can easily be prevented.
Types of fenders
| Type fender | Features | Best Application |
|---|---|---|
| Cylindrical fender | Can be mounted elongated, horizontally or vertically | General use in motor and sailing boats |
| Ball or ball fender | Round, filled with air, high damping capacity | Extra protection for high scaffolding or rough conditions |
| Scaffold fender | Permanently attached to the scaffolding | Ideal for permanent moorings, protects during mooring |
| Bow fender | Specially shaped for the bow | Protects the front of the boat when mooring |
| Flat fender | Thinner and lightweight | Small boats or as an extra buffer when space is limited |
How do you determine the correct size?
The number and size of your fenders depends on the boat length and the wind area:
- Rule of thumb number: at least 1 fender per 2–3 meters of boat length, preferably with one spare.
- Rule of thumb size: the larger and heavier the boat, the thicker the fender.
Indication:
- Boat up to 6 meters → Ø 10–15 cm
- Boat 6–9 meters → Ø 15–20 cm
- Boat 9–12 meters → Ø 20–25 cm
- Boat 12+ meters → Ø 25–30 cm
How much pressure should a fender have?
Most inflatable fenders have a recommended pressure of 0.15–0.2 bar . Overinflating reduces the damping capacity. Test regularly: a fender should yield slightly when pressed with your thumb.
Maintenance & accessories
- Maintenance: Clean fenders with water or a special fender cleaner to prevent discoloration.
- Fender lines: Use strong fender lines to hang fenders at the correct height.
- Fender covers: protect against dirt, UV rays, and squeaking noises during the night. View our fender covers .
Frequently asked questions about fenders
How many fenders do I need?
Rule of thumb: 1 fender per 2–3 meters of boat length, with at least 2 per side. For boats 10 meters or longer, often 3–4 per side.
What is better: a cylindrical or a spherical fender?
Cylindrical fenders are the most versatile. Ball fenders provide extra protection in rough conditions or on high scaffolding.
How do I keep my fenders clean?
Use water or a special fender cleaner. Fender covers are ideal for long-lasting, beautiful results.