It's always best to get yourself covered before you head for the piste. If your flight gets cancelled, the weather on the slopes is dreadful, an avalanche hits, all your snowboards get destroyed, you break both your legs and your face or everything fails, you'll want to save yourself the cost. Snowboard insurance usually costs about £15-25 to get a really solid package, it's probably worth upgrading to make sure you're completely sorted. It's probably worth it in case it all goes wrong, you get to buy your holiday again for the next snowboarding season.
Club Direct - Snowboard Insurance from around £8 - Protects you from all the usual stuff, plus avalanche, bad weather and piste closure cover. Which is useful.
Insure With Ease - Ski and snowboarding insurance from about £11 - All the usual stuff is included, but you can upgrade to Gold to get extra cover if you fancy it.