Festive dips.

Fancy dress looks rather different with the sea behind it. Tenby’s Boxing Day Swim, Saundersfoot’s New Year’s Day Swim and South Queensferry’s Loony Dook all make a festive gathering out of an unlikely trip into the water. London’s Peter Pan Cup is a different spectacle altogether: a club race in the Serpentine on Christmas morning. Choose each event for what it actually is, because not every photo of a wintry swimmer means anyone can wade in.

Taking part and watching are two complete ways to enjoy the day. The Peter Pan Cup is for qualified club members; as a visitor, you come to cheer from the bank. The other events publish their own registration, fundraising, supervision and costume arrangements, and those can change from one edition to the next. Check the organiser's latest information before paying, promising a charity challenge or pouring hours into an outfit. You can support friends and the event without getting wet at all.

Plan what happens straight afterwards as carefully as your arrival. Swimmers need to follow the event's safety instructions and sort out their own changing and journey home; spectators need to know where to meet them without blocking the crowd. If your plan relies on somewhere warm indoors, make sure it's genuinely open. A café's normal menu or a nearby hotel tells you nothing about Christmas or New Year opening, and a seasonal transport timetable may look very different from an ordinary weekday.

Use these guides to tell confirmed details from a tradition's usual date. Tenby’s website may carry material from more than one year, while different Loony Dook listings can describe different arrangements or fundraising groups. The current Saundersfoot guide points you to that organiser's own programme and entry instructions. Read the page for your particular swim before deciding your role. And if your preferred way to greet the season involves a coat, a flask and emphatic applause from dry land, there's absolutely a place for you.