Diving into shark-infested waters might jeopardize your personal life insurance or key man insurance (a policy that names your company as the beneficiary). If you become fish food, and your plan went into effect two years ago, the carrier could contest the payout if you had claimed not to indulge in risky pastimes.

If you don't have a policy yet, you may have a hard time getting one if the underwriters know about your penchant for HALO jumping, says Byron Udell, founder of AccuQuote, a life insurance brokerage in Wheeling, Illinois. At the very least, he says, you'll have to pay extra, sometimes even two to three times more than you would otherwise. Certain insurance companies will exclude dangerous hobbies from the policy in exchange for lower premiums, but the practice has become rare, Udell says, because some courts have ordered insurers to pay up regardless of the exclusions.