A travel insurance policy to cover theft, loss and medical problems is always a good idea. Worldwide travel insurance is available at www.lonelyplanet.com/travel-insurance. You can buy, extend and claim online anytime – even if you’re already on the road.
Some insurance policies specifically exclude 'dangerous activities', which can include scuba-diving. Note that policies don't usually cover dental work, only pain relief. Check the small print before signing up.
You may prefer to have an insurance policy that pays doctors or hospitals directly rather than you having to pay on the spot and claim later. If you have to claim later, make sure you keep all documentation. Some policies ask you to call (reverse charges) a centre in your home country, where an immediate assessment of your problem is made.