Travel insurance is definately definately worth it. But shop around coz you can get quotes that very massively.
In 2006 I went snowboarding in Franc - I had really cheap travel insurance that really only covered the basics - but thank god I did - I fell awkwardly in my class and broke my wrist - after the snow ambulance, emergency medical, emergency cast, transfer to hospital, xrays, flying in my anasteiologist and surgoen (my wristbroke right through and he bones and moved) follow up and 2 nights in holidays my total bill was $84,000euros!!! my travel insurance covered the lot, and follow up physio appointments, and the change to my travel plans.
i am recommending that my guests my age check out world nomads- they cover more adventerous activities and have great reviews - and are pretty cheap to boot!