Hi SueInBoston, I have looked at my old emails, and found that we took an Ocean Joy trip in March. As a nice feature, they had a photographer who took your photo while you were snorkeling. And they managed to make me look good in the photo! Another nice feature if you wear glasses, or wear contacts and don't want to try snorkeling while wearing them: They had prescription goggles, strong enough for me, in terms of the diopters. The lenses were some variety of polymer. Later, ahead of a cruise, I purchased prescription goggles to use at
Castaway Cay. They had much heavier, glass lenses. Although they were fine, before we go on a
Disney cruise again, I will be looking for goggles with polymer lenses.
I am not sure whether we took a trip with that same company in August or not. August is a wonderful month to go!
I believe that many of the snorkeling tour boats put fish food in the water (they do it somewhat discreetly) to attract more fish. This may make some people uncomfortable.
Looking at the trips that are currently listed on Viator, the Oahu Catamaran Cruise: Wildlife, Snorkeling, and a Hawaiian Meal looks closest to the one that we took in August. It leaves from Ko Olina, which is convenient. The meal is okay. The snorkeling was excellent! The departure site is within walking distance from Aulani (maybe about a mile away). On one trip, one of the tour operators told us a lot about Hawaii while we were heading out to the snorkeling site, and I enjoyed the commentary.
We picked tours that were on the "Excursions" list for Aulani at the time. Aulani isn't showing snorkeling trips currently. Some of the snorkeling trips seemed to be of the "two or three men and a boat" variety, including the ones we went on! They seemed perfectly safe to me. It is possible that these tour companies have been badly impacted by the pandemic. They may return to operation (soon, I hope). Some of the snorkeling trips are pretty brief. I would recommend one that is at least three hours.
I am sure that other posters have more extensive experience with the snorkeling trips and can provide better advice!