Must I winterise the boat?

Short answer

Whether winterising is a duty with a sanction or evidence with a reward makes the whole difference in a claim.

Get a quote Boat insurance overview

Almost every policy expects you to protect the boat against frost. The difference lies in what happens if you did not, or did not do it fully, and there are two quite distinct constructions.

The first treats missing frost protection as a lack of care and excludes the resulting damage as such. That is the hard version: an exclusion knows no grading by fault, no prior warning and no argument about whether it would have happened anyway. The second works with evidence: whoever can show the measures pays the agreed excess, whoever cannot pays a higher one. Cover stands in both cases.

For you this is the most important question of the whole subject, more important than any limit. Check whether frost protection in your policy is framed as a duty, an exclusion or a matter of evidence. And in any case keep a short record: date, work done, photographs. Twenty minutes in November is the difference in February between reimbursement and argument.

What belongs in such a record?

Date, which systems were drained or filled with antifreeze, which product, plus photographs of the open cocks and the gauges. One page is enough.

Does it apply if the boat winters afloat?

Then especially. Several wordings tie cover for wintering afloat to additional requirements. Read that paragraph before you decide, not after.

Frost damage Storm warning Left unattended