Once I mentioned I dive, my optometrist immediately insisted I switch to dailies during dive trips. There is a risk if you get fresh or saltwater in your eye you develop an infection from bacteria or fungus sticking to the contact. By throwing away the contact at the end of the day you drastically reduce the risk. She has seen this occur and was so insistent that she offered to give me trial dailies to wear.
It is more like a rule that if contact lenses must be used while swimming/diving/even showering, disposable dailies should be used and discarded as soon as convenient after the exposure. Infections are rare, but exposure to water and overnight use of contacts are predisposing factors.
I have a very good prescription mask (Seavision). That said, I usually choose to dive with daily contacts. I have done mask removal drills and also had my mask dislodged during a cave drill while wearing contacts without any problems. I like dailies. I have also 30-day contacts, but don't find them better in any way except being less expensive to use.