There's a particular kind of confidence that comes from launching a boat you've actually looked at. Not "I think I changed the impeller last year" or "the zincs were fine when I hauled." Looked at — systematically, in order, with notes. Spring commissioning done properly means you leave the dock knowing exactly what condition your boat is in. Everything else is guessing.
When to Haul, When to Stay In
In climates where temperatures stay above freezing through winter — the Pacific Northwest south of Puget Sound, most of the Bay Area, coastal Florida and the Gulf — there's a real argument for keeping the boat in the water year-round and doing a shorter spring check rather than a full haul. The savings in haulout fees and the time you get back are meaningful. The tradeoff is that you don't get eyes on the bottom. You're relying on the last haulout inspection and whatever a diver can tell you.
In cold climates — anywhere with sustained freezing temperatures — the boat comes out. Not because the water will freeze around it (it won't, in most marinas) but because thru-hulls, raw water systems, and anything else with trapped water needs to be properly winterized, and you can't do that reliably in the water. The hull also benefits from an annual inspection and fresh bottom paint. If you're on the fence: haul. The cost of one missed osmotic blister or a thru-hull that's been silently failing is much higher than a haulout fee.
Hull
Start with the bottom paint. Ablative paints wear down and slough off through the season; by spring you're looking at areas that may be worn through to the substrate, particularly around the bow and at the waterline where turbulence is highest. If you can see the primer or gelcoat through the paint, those areas get another coat before launch. Check for patches where the paint is peeling or bubbling — that's usually a sign of moisture intrusion beneath.
Osmotic blisters form when water migrates through the gelcoat into the laminate and reacts with materials in the fiberglass. They look like small bubbles, anywhere from pea-sized to an inch or more across. Small blisters that haven't broken the gelcoat can be monitored. A blister that's opened and weeping, or a concentrated patch of blistering in one area, warrants a conversation with a qualified surveyor or boatyard before you go offshore. Left untreated for years, osmotic damage becomes a major structural repair.
Every thru-hull gets operated. Close it, open it, close it, open it. If a seacock hasn't moved in several years, it may be frozen in place — bronze seacocks can develop dezincification and fail suddenly. The time to discover a frozen seacock is in the boatyard, not in a seaway. Any seacock that won't operate freely gets serviced or replaced before launch. Check the hose connections at each seacock while you're there; hose clamps corrode and loosen, and a failed hose at a thru-hull is a fast sinking scenario.
Zincs: shaft zinc, keel zinc if fitted, rudder zinc. If they're more than 50% consumed, replace them. If you hauled in the fall and they're already gone, you either sized them wrong, there's stray current in the marina, or both.
Engine
Oil and filter change if you didn't do it in the fall — ideally you did, because acid byproducts in used oil corrode bearing surfaces over a long winter layup. Change it now if not done. Check the raw water impeller: replace it. Every spring, regardless of what you think the hours are. The impeller is a $20–40 part; an overheated engine can cost you a head gasket or worse. Carry two spares. Check the coolant — look at the level in the overflow reservoir and check the color; if it's rusty or dark, flush and replace it. Inspect the alternator belt and raw water pump belt for cracking, glazing, or fraying. Replace any belt you're uncertain about; they're cheap and readily available at the dock, not necessarily a mile offshore.
Change the primary and secondary fuel filters if you didn't do it in the fall. Diesel that's been sitting develops microbial growth at the water-fuel interface, and that sludge gets caught by the filters. Start the engine at the dock and let it run to full operating temperature. Watch the gauges: oil pressure should come up within seconds, coolant temp should stabilize in the normal range, and you should see raw water exhaust from the stern within 30 seconds of startup. If the temperature climbs past normal, shut down immediately — don't run an overheating engine to see if it clears.
Rigging
Standing rigging inspection means getting close, not a cursory look from the deck. Go up the mast or hire someone to go up. At the masthead: look at the forestay and backstay terminations, the halyard sheaves, and the condition of the wire where it exits any swage fitting. A cracked swage fitting — even a hairline crack — means replace the stay before offshore sailing. Come back down and check every turnbuckle: the cotter pins should be in place and bent, the toggle fork and eyes should move freely, the threaded section should show no signs of corrosion. If any cotter pin is missing, that's not a "note it and do it later" item.
The furler drum at the base of the forestay is a common failure point. Spin it by hand — it should rotate smoothly with no grinding or catching. Check the foil sections above it for straightness. Running rigging wear concentrates at contact points: where the jib sheets cross the shrouds, where the mainsheet runs through blocks, where halyards pass through clutches. Run your hand along the sheet in those areas and feel for flat spots, broken strands, or excessive softening of the braid. A sheet that has been running in the same position for several seasons may be worn significantly even if it looks acceptable visually. Mark halyards so you can end-for-end them annually and get more life out of them.
Safety Gear
This section has hard expiry dates that don't care about your schedule. EPIRBs have a battery expiry date and a hydrostatic release expiry date — they're often different, and both have to be current for the unit to be legal and reliable. Check both dates now, not the morning before you leave on a passage. Flares expire too; in the US, USCG-approved flares have an expiry date printed on them and are no longer considered compliant after that date. Most flares last three years. If you can't remember when you bought them, replace them.
Life jackets: inflate the bladder on any inflatable PFD and watch it for 30 minutes. If it holds pressure, you're good. If it doesn't, it needs a new bladder or a new CO2 cartridge and oral inflation tube, depending on where it's leaking. Check the automatic inflation pill — it's a small white tablet that dissolves in water and triggers inflation. There's an expiry date on it. Inspect the webbing and buckles for UV degradation, particularly on PFDs that have spent seasons in the cockpit or on a lifeline. Webbing that's stiff, cracked, or heavily faded should be replaced; the buckle you need to open in the water should work. Safety tethers: inspect the webbing the same way and check that the snap hooks open cleanly and latch positively under load.
Systems
Battery capacity test — not just "starts the engine." A battery that will turn over the engine may still be at 50% of rated capacity and will leave you without lights after a few hours at anchor. A proper test means checking with a load tester or measuring resting voltage, then load voltage, or ideally using a battery monitor that's been tracking amp-hours. Batteries that are more than 4–5 years old in a marine environment should be tested and replaced if they're not holding charge. Check all battery connections; corroded terminals are the most common cause of mysterious electrical failures.
Bilge pump test: put water in the bilge and run the automatic float switch. Confirm it pumps. Confirm the discharge is clear. A bilge pump that runs and doesn't move water — blocked strainer, failed impeller, clogged discharge — is worse than useless because the automatic switch won't alert you to a problem. Navigation lights: turn on running lights, steaming light, anchor light, and masthead tricolor if fitted. Walk the boat and confirm they work. Replace bulbs before you go, not underway in the dark.
The Written Checklist
Memory fails in predictable ways: you remember what you checked most recently, what caused a problem last year, and what you feel good about. You forget what you haven't needed to think about in a few seasons. A written checklist doesn't have those biases. It asks you about the thru-hull you haven't touched in three years, the EPIRB battery that was good last spring, the bilge pump that's never failed.
The checklist should include a date for each item and a line for notes. "Replaced" is not the same note as "checked, appears good, original hardware." In three years when you're trying to remember whether the backstay swage fitting was replaced or just inspected, that note matters. Keep the commissioning records with the boat's papers, not in your phone. Boats get sold, phones get replaced; the paper record travels with the vessel and tells the next owner what was done and when.
The format doesn't need to be complicated. A single sheet of paper with category headings, each item, and three columns — date checked, condition, action taken — covers everything you need. Review it against the previous year before you start. The items you always check are already on the list. The items from last year that needed follow-up are also on the list. You're not starting from memory; you're continuing a record.