The consumables an old boat eats
Nothing on this list is optional and nothing on it is expensive. Buy them before the season, not during a haulout when you are paying yard rates.
Every season
Raw water pump impeller (and a spare)
Rubber takes a set and vanes break off downstream into the heat exchanger. Cheap part, expensive consequence.
Primary and secondary fuel filters
The single most common cause of a dead diesel in a seaway is dirty fuel, not a dead engine.
Zinc anodes, hull and heat exchanger pencil zincs
A consumed zinc is doing its job. A missing one means your prop, shaft and heat exchanger are next.
Impeller-safe engine oil and filter
Keep aboard
Assorted hose clamps, all 316 stainless
Double-clamp every below-waterline hose. 304 clamps rust away and are commonly sold as marine grade.
Softwood plugs, one per through-hull
Tied to the fitting they serve. This is the difference between a scare and a sinking.
Spare belts for every driven accessory
Borrow before you buy. A moisture meter and a borescope are the two expensive items here, and both are worth renting or borrowing for one inspection. If you are looking at three or four candidates, buy them: they will pay for themselves on the first finding.
The pre-purchase inspection kit for your boat
Having the tools is half of it. The kit tells you where to point them on your exact model, what each finding costs to put right, and which ones should end the deal.
See the inspection kits