2 min read · Updated 18 June 2026
Hydraulics move and hold the heavily loaded parts of a racing yacht — most importantly the canting keel, but also the rig and sail controls where the forces are too high to manage by hand. They give the crew enormous, finely adjustable, lockable power over the systems that make a modern boat fast, which is why they sit at the heart of any grand-prix yacht's engineering.
Why hydraulics
Some of the loads on a racing yacht are immense, and some settings have to be held rock-solid under strain. Rope and winches can't always do that job — they would slip, chafe or simply be impractical at the forces involved. Hydraulics solve it: a pressurised fluid system delivers huge mechanical force, allows very fine adjustment, and locks a setting firmly in place under load. That combination is exactly what the keel and the high-load rig controls need.
Swinging the keel
The headline job is the canting keel. One or more hydraulic rams connect to the top of the keel fin; a pump pressurises the fluid, the ram drives the keel out to windward, and valves hold it at the chosen cant angle. The system is under enormous strain the whole time, because it is holding a heavy ballast bulb out to the side against the heeling force of the wind. It is the single most demanding hydraulic task on the boat.
Trimming the rig
Beyond the keel, hydraulics adjust the high-load rig and sail controls:
- Backstay and forestay — to bend the mast and control forestay tension and sag, shaping the sails
- Boom vang (kicker) — controlling leech tension and mainsail twist
- Cunningham and outhaul — fine-tuning mainsail shape
These are the controls that tune the rig and sails through the wind range, and on a powerful boat the loads make hydraulic control the practical choice.
What powers it, and who controls it
The pressure usually comes from manual hydraulic pumps, often driven by the same grinding pedestals and winch handles the crew use for the sails, or from a dedicated pump. The crew builds pressure and valves direct it to whichever function is being worked. Control is through panels and levers near the relevant crew — and on a canting-keel boat like the Melges 40, the keel itself is worked from a keypad at the tactician's position, so the same person managing tactics also manages the ballast. For the wider vocabulary, see the sailing terms glossary.
Frequently asked questions
- What do hydraulics do on a racing yacht?
- Hydraulics move and hold the most heavily loaded systems on the boat. The biggest job is swinging a canting keel from side to side, but hydraulics also drive rig and sail controls — the backstay, forestay, boom vang, cunningham and outhaul — where loads are too high to adjust by hand and need to be held precisely under strain.
- How is a canting keel moved hydraulically?
- A canting keel is swung by one or more hydraulic rams connected to the top of the keel fin. A pump pressurises hydraulic fluid, which drives the ram to push the keel to windward, and valves lock it at the chosen cant angle. The system has to handle enormous loads, because it is holding a heavy ballast bulb out to the side against the force of the wind.
- What powers the hydraulics?
- On most racing yachts the hydraulics are powered by manual hydraulic pumps — often driven by the same grinding pedestals and winch handles the crew use for the sails — or by a dedicated pump. The crew builds pressure by pumping or grinding, and valves direct that pressure to the keel ram or the control being adjusted.
- Why use hydraulics instead of ropes and winches?
- Some loads are simply too high to manage with rope and too important to let slip. Hydraulics give enormous mechanical force, very fine adjustment, and the ability to lock a setting solidly in place under load. That makes them ideal for the keel and for high-load rig controls, where a rope system would be impractical or unsafe.
- How does the crew control the hydraulics?
- Through valves and control panels. On a canting-keel boat like the Melges 40 the keel is worked from a keypad at the tactician's position, while rig and sail controls are adjusted from panels or levers near the relevant crew. The person calls for pressure, directs it to the right function, and locks it off.