As a ski instructor or a snow board instructor you’re insured against third-party liability during working hours by the ski school you’re working for.
You’re also insured against medical expenses when the medical complaints have been originated through working at the ski school.
But when you’re going to the piste in your own (free) time or your camera is being stolen, you’re not insured by the ski school. For this purpose you need a solid travel insurance with winter sport coverage of your own.
Shortly in this place you’ll find a good offer to take out such a travel insurance.
This travel insurance also covers winter sports and moreover it allows you to work. In case of a “normal” travel insurance as a matter of fact you’re not allowed to be at work abroad and you’re even not allowed to stay abroad longer than 60 days. So if you should keep working at the ski school during the whole winter season, you’ll need a special travel insurance.