We just got back from the Big Island last month and we did several days of diving with Jack's Diving Locker, who I would say are really perfect for a beginner diver. The Manta night dive is pretty cool, ranks as one of my top dives ever. It's very easy, not very deep, they provided lights and all you do is make a big circle on a mostly sandy bottom with just about every other dive operator in the area. We only saw maybe 4 or so but they were large and literally swim right over you, the lights look a little like an underwater disco. I would not miss this dive! Also we saw spinner dolphins jumping and spinning several days while on the boat (very close) and heard them underwater but did not see them diving! Personally I would avoid shore dives in a new place and still being a newer diver, though it sure would be a LOT cheaper!
As for the Pelagic Magic, I don't know about this dive for a beginner. If you are comfortable with night dives and you have been in open water before and have a fair amount of dives under your belt then I would say go for it but I think this dive could easily freak out a beginner diver. We were supposedly in 10,000 feet of open ocean, it's very dark and they hook individual lines to you and you jump in and float about 40-50 feet below the boat. Despite being on a line, there still can be current and it's easy to get a little tangled in the lines if you aren't paying attention and you want to make sure you don't start surfacing/drifting under the boat. Plus you don't go on this dive if you will freak out about what you can't see or what you think you might be seeing! I was the second person in the water and the last to come out and apparently most of us missed a very big fight between a couple that came up early during our dive and my best guess is something happened that made her freak out underwater.
. It's also 7' or less deep for a very long way out so good for inexperienced snorkelers.
