Short answer
A mast is unstepped by disconnecting deck-level wiring and plumbing, slackening and releasing the standing rigging in a controlled order while a crane takes the weight, lifting the spar clear, and laying it on padded trestles. It is crane work with people beneath a suspended load, and is not an owner task on a keel-stepped rig.
Unstepping is a coordinated lift, not a disassembly job. The crane takes the mast weight before the rigging is released, and the order in which stays are slackened keeps the spar controlled through the process. Getting that order wrong is how masts get bent or dropped.
Keel-stepped rigs add complexity: the spar passes through the deck at the partners, and wiring, plumbing and sometimes hydraulics must be disconnected and labelled first. Deck-stepped rigs are simpler but still a crane lift.
Where the mast goes afterwards matters as much as the lift. A spar laid on inadequate supports can take a permanent set. Padded trestles at the right spacing, with the mast supported along its length, protect the section and the fittings on it.
This is the point in a project where hidden condition becomes visible — mast step corrosion, partner damage, spreader roots and internal wiring. Budget for it. See how to prepare for a re-rig and the masts and spars guide.
Key facts
- Equipment
- Crane or travel lift, padded trestles, strops rated for the spar
- Keel-stepped extra work
- Wiring, plumbing and hydraulics disconnected and labelled at the partners
- Main risk
- Suspended load with people working beneath it
- After the lift
- Support along the full length to prevent a permanent set
- Owner task?
- No — crane operation and load control are professional work
Full background: read the guide