I'm a licensed life insurance agent (amongst other things) here in Canada and what happens here with people who dive, it really depends on the situation. Divers are asked to fill out an addendum to the application to explain the details of their diving, including types of dives, frequency, certification level, etc. For new divers and those who are planning to learn, it can potentially be a bit more of an issue (note that it may not always be the case). For experienced divers and those who dive frequently (as well as professionals such as DMs and Instructors) it is generally not an issue, and your premiums would be no different than if you were a non-diver. As long as you answer the questions to the best of your knowledge, you generally should have no problems.