In general this will be at the discretion of the boat owner, although some European countries do require an ICC certificate (equivalent to RYA Day Skipper) for boats over a certain size. An RYA Day Skipper certificate is usually a safe bet for most boats; or submit a sailing CV if you’ve done a lot of boating but never taken this out. Smaller boats will need less experience, but boat owners will usually like to know that you’ve at least handled a boat before.
If in doubt ask the boat owner, and there’s always the option of booking a skipper for the trip. This has its own benefits and will allow you to kick back with your family and friends; relax into the sail whilst someone else gets you from A to B. Hosts are also available for meal provisioning, and full crews for larger boats. See the optional extras on each individual boat listing for what’s available.
We say that 6-8 weeks a year is as much as is realistic to expect on average. There’s more chance of getting to nearer the top end of this with favourable reviews on the site and positive customer feedback. Just choose the dates you want to use your boat for, then leave it to us to fill it on the other weeks.
Generally we advise that it will not be possible to make any significant profit, but chartering your boat out will likely cover annual running costs of the boat, including mooring fees, insurance and maintenance costs.