I will be taking a cruise in March that offers a PADI certification class on board. Is it worth doing the online class before going? Spending 4 of 5 hours a day for two days while at sea is not an issue, but if the online class would be helpful Im up for that too.
This particular class material you are looking at is a different Training Agency. While it would help familliarize yourself with what is going on, it will be of no real help over all. By taking the PADI online class you will at least clear out all the course work and have the completion certificate to take to your instructor. That will save you a little time.