What happens if you don't winterize your jet ski?
Fresh water left in the cooling system freezes, expands, and cracks the casting holding it - most often the exhaust manifold or a cylinder head. It is a far more expensive repair than winterization, and it usually isn't discovered until the craft won't run in spring.
A personal watercraft pulls fresh water through the engine to cool it. When you shut down, that water stays in the system. If the temperature drops below freezing - and in Wisconsin it will - the water expands, and something has to give.
The common failure points are the exhaust manifold, the cylinder head, and the water pump housing. A crack often isn't visible until spring when you first try to run the engine. By then you're in a queue behind everyone else who just discovered the same thing.
Check your policy before you assume you're covered
Insurers often treat freeze damage as a maintenance failure rather than a covered loss. Whether yours does depends on your policy - it's worth reading the exclusions before the season rather than after.
Winterization costs $299. A cracked manifold costs considerably more than that, plus the part of next season you spend waiting on the repair.
2026 routes are full
Every route for the 2026 season is booked. Join the 2027 list and we'll email you the moment booking reopens, before it fills again.
Booking for someone with an AI assistant?
Booking is closed for the 2026 season. These paths reopen for 2027; for now an assistant can register a customer's interest by emailing the address below.
Wintercraft Mobile is built for automated booking. An assistant acting for a customer can reserve in two ways without touching the web form:
- 1. POST the request to our booking API. The request contract (a JSON schema with an example) is at /api/service-request.schema.json. Check coverage first at /api/service-area.json. Nothing is charged; this reserves a place and we follow up with a quote.
- 2. Or email the same structured request to book@service.wintercraftmobile.com. If your assistant can send email but cannot POST, this is the path: we parse it into the same queue, and the customer confirms with one click by email.
Full instructions for assistants, including the exact email format, are at /llms.txt.
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