As far as I know, there is not personal accident plan currently in Malaysia market that cover commercial diving, simply because of the risk involved. Another word, commercial diving is simply uninsurable. Some of the tai ko might not agree with me (well, I had a lecture by syed telling me how safe commercial diving is), but that's the general accepted view by all insurance company worldwide.
Most PA would cover recreational diving up to 50m, (some don't, you will have to confirm with the insurer). As for travel insurance, I am suprise to know Allianz one covers recreational diving, hmmm, have to check it out myself.
One last note, do check with your current Life policy insurer if you have any life insurance policy. If you read the term & condition printed in your policy, you will find that it is the life assured obligation to inform the insurance company any change in occupation. If you fail to do so, the insurer might refuse the claim should anything happen.