Quick answer, get in your boat and head out to the dive spot. Fly a "diver down" flag up on the boat along with a someone on board. Dive dive dive!
Long answer, unless they people are good friends of yours (and even that wont protect you), I wouldn't take anyone out unless I had ample liability insurance for the boat/passangers. If these are paying customers you would most likely need insurance for "charter" boats or boats for hire.
Based on your name I assume you are a PADI Dive Master? If so, brush up on your insurance policy for your Dive Master and find out what it will and won't cover.
Chances are, you'll find that the insurance you have wont cover you also acting as the "captain" if something goes wrong.
If these are close friends of yours, I see no harm. If these are people you are taking out on a trip that you're doing as a good gesture or if they are paying I would look at the bigger picture.