Spring Recommissioning Checklist: Getting Your Boat Back in the Water

Start from the lay-up record: what was disabled

Recommissioning is the lay-up in reverse: every protective step taken in autumn needs undoing in spring. The usual mistakes are forgotten steps rather than technical ones: an engine started with its air intake still sealed, an impeller left in a drawer, a drain bung that never went back in. Read last autumn's lay-up record and turn each line into a job; if there isn't one, walk round the boat with this list.

• Air intake and exhaust sealed, “do not start” tag on the helm: seals to remove, tag last.
• Raw-water impeller removed: to refit, or replace, with a sound cover gasket.
• Raw-water circuit, fresh water and heads full of antifreeze: to flush through.
• Calorifier drained or on bypass: back in circuit before the tanks are filled.
• Batteries taken home or isolated: to charge and refit.
• Drain bung out and seacocks left open ashore: bung back in, seacocks closed before relaunch.
• Gear taken off (liferaft, sails, portable electronics, cushions): to collect and stow.

A timeline from late winter to the first sail

Spring is busy for boatyards and some parts take a while to arrive, so recommissioning starts with the diary.

• A few weeks before: reread the lay-up record, book the relaunch, order an impeller, filters, anodes and flares, and collect the liferaft from servicing.
• Relaunch day: leak checks, then the first start.
• The following days, on the pontoon: water systems, electrics, safety kit, rig and sails, then the sea trial.

Hull, running gear and seacocks: jobs to finish ashore

With the boat in her cradle, everything below the waterline can be reached without a diver. Antifouling goes on a clean, dry hull, and each paint has its own drying time before immersion. A badly wasted anode no longer protects the metal underwater; the yard can tell you whether it needs replacing and which alloy suits the water the boat is kept in (salt, brackish or fresh).

• Hull and gelcoat: blisters, knocks and cracks, starting with any defects noted in autumn.
• Anodes: shaft, propeller, saildrive or sterndrive leg, bow thruster and engine.
• Propeller (damage, play), shaft and cutless bearing, stern gland or shaft seal, rudder bearings; on a saildrive, the diaphragm.
• Seacocks: operate every one and check the hoses and hose clips below the waterline.
• Depth, speed and other through-hull transducers refitted and watertight; drain bung in.

Inboard diesel: a careful first start

A well laid-up diesel starts without fuss, provided you don't rush it. Over the winter, water held by the biodiesel (FAME) in pump diesel has settled in the tank and the water separator, and the raw-water circuit is still full of antifreeze. Started ashore, the engine must be fed with water, through a hose on the raw-water inlet or with the intake hose in a bucket, and never run dry, because an impeller is damaged very quickly without water. The antifreeze coming out of the exhaust can then be caught in a bucket instead of going into the marina. For oil grades, coolant, torque settings and intervals, follow the engine manufacturer's manual.

• Drain water and sludge from the separator bowl; if in doubt about the fuel, change the filters before starting.
• If the oil wasn't changed in autumn, change it now, with the filter.
• Check levels: engine oil, closed-circuit coolant, gearbox or saildrive oil.
• Inspect belts, hoses and hose clips; look for oil or diesel under the engine.
• Refit the impeller, remove the intake and exhaust seals, open the raw-water seacock.
• Start, then check straight away that water is coming out of the exhaust; if not, stop and find out why.
• Bring it up to temperature, watching warning lights, charging and leaks, then recheck levels with the engine off.
• Write the hour-meter reading on the record.

Outboards and petrol engines

An outboard needs only a few checks; fuel is the delicate part. Standard petrol in Great Britain has been E10 since September 2021, and the government lists boats among the equipment that may not be compatible with it (gov.uk, “E10 petrol explained”, consulted 1 October 2026). Ethanol blends also keep poorly in a tank or a carburettor bowl: if the fuel wasn't stabilised in autumn, drain it and dispose of it properly rather than burning it.

• Check the gearcase oil: milky oil means water is getting in, so a seal needs replacing before the season.
• Four-strokes: oil level, and an oil change if it wasn't done in autumn.
• Spark plugs, fuel line, primer bulb and connectors: no cracks, no leaks.
• Refit the propeller with grease on the shaft, split pin and nut in place.
• Start on flushing muffs or in a test tank and check that the tell-tale gives a steady stream of cooling water.

Fresh water, heads and bilge

Flush the non-toxic winter antifreeze out with fresh water until it runs clear at every tap. This is also when you find out whether frost has split anything: a cracked fitting often only shows once the system is back under pressure.

• Run the pump, open every hot and cold tap, transom shower included, and look for leaks.
• Heads: flush through, check the seals and the holding-tank valves.
• Bilge pump: test the float switch on automatic, then the manual switch.
• Bilge clean and dry before relaunch, so any water afterwards points to a leak.

Batteries and electrics

A battery charged and isolated for the winter comes back without trouble; one left connected without a charger may have been deeply discharged. Charge each bank before refitting it, then test the circuits one by one on the pontoon rather than finding a dead navigation light at dusk.

• Terminals tight and protected against corrosion, polarity checked.
• Test navigation lights, VHF, instruments, bilge pump, windlass, bow thruster and cabin lights.
• Check the shore-power charger and, with the engine running, the alternator output.

Safety kit and paperwork

For UK pleasure boats under 13.7 m, the RYA notes that there are no statutory safety equipment requirements beyond those set out in SOLAS V, and publishes a table showing what SOLAS V requires and what else is good practice to carry (RYA, “Equipment for UK Pleasure Vessels”, consulted 1 October 2026). Other flags and commercial use have their own rules. Out-of-date flares need planning: HM Coastguard no longer takes them back, and it is illegal to dump them at sea or on land, or to let them off except in an emergency. The RYA points boaters to the original supplier, a liferaft service agent, their marina or The Green Blue's map of disposal points (RYA, “Disposing of out of date flares”, consulted 1 October 2026).

• Lifejackets: straps and stitching; on auto-inflating ones, the gas cylinder and firing mechanism.
• Fire extinguishers: service or replacement date, and the gauge in the green where there is one.
• Flares, EPIRB or PLB, liferaft, first-aid kit: expiry and service dates.
• Lifebuoy, anchor and rode, bailer and torch in place.
• Paperwork: registration papers if the boat is registered, insurance certificate, berth contract.

Relaunch day and the sea trial

Some checks can only be done afloat. Stay aboard for the relaunch, or ask the yard to leave the boat in the slings for a few minutes: if water is coming in, she can still be lifted out. Then take her on a short sea trial in easy weather, close to home.

• In the slings: open the seacocks one by one; no water at the through-hulls, shaft, rudder or saildrive.
• On the pontoon: start, water at the exhaust, up to temperature, ahead and astern.
• Under way: steering, instruments, autopilot; on a sailing yacht, set each sail and try the furlers and winches.
• Back alongside: a dry bilge, levels, belt tension, and a list of what still needs sorting.

Example recommissioning record (fictional)

Fictional example, following on from the lay-up record in our winterisation checklist: a 10 m (33 ft) sailing yacht with an inboard diesel and a saildrive, laid up ashore in a south-coast boatyard with 1,412 hours on the meter. The spring record works through every “to undo in spring” line from the autumn.

• Header: work by the yard's engineer from 22 March 2027, relaunch on 9 April; hour meter still at 1,412 h, so nobody ran the engine over the winter.
• Ashore: the three blisters from autumn looked at by the yard, to be monitored; propeller anode replaced, saildrive diaphragm checked, seacocks closed.
• Engine: separator drained (a little water), impeller collected from the chart table and refitted, seals removed and then the helm tag, levels checked.
• Water and power: calorifier back in circuit, systems flushed, bilge pump tested; batteries brought back, charged and refitted.
• Safety: liferaft back from servicing (next date noted), new flares, old ones handed in for disposal; sails bent on.
• Afloat: no leaks; sea trial on 10 April, hour meter at 1,414 h; one navigation light to fix before the season.

Recommissioning several boats from one checklist

In Captain Crews, marine management software, you save this checklist once as a work template called “Recommissioning” and set it to repeat every year in the month you choose; it then creates one work order for each boat and technician. The engine-hours step updates the hour meter, a job can't be closed while any step is neither ticked nor skipped, and last autumn's lay-up job is in the boat's maintenance log. The safety register warns you before flares or extinguishers expire.