Navigator's & General, part of Zurich Financial Services, has launched a quote-and-cover facility for ships on its website.
It will accept any vessel from a £1,000 dinghy to a £150,000 yacht or motorboat.
Vessels exceeding this value will be referred to underwriters, and a quote will be provided within three working days.
If an online quote is acceptable, it can be paid for immediately with a credit or debit card.