Nice. Kona coast has some great diving, both from shore and boat. My personal wetsuite rule for Hawaii is: May - October 3mm. November - April 5mm. I was there in November and temps were 75 - 78˚ and I was very glad I had the 5mm. There was one DM I saw in a 3mm, but most of them were in 5s and a few in 7s.
Off Kona you can also run into cold spots. These are due to the fact that fresh water runs off the island not in rivers but by percolating down through the porous lava rock and upwelling as cold springs off shore. I've hit some very cold spring water on dives that made me glad I had the 5mm.
However, if you are going to just do a few dives over the week the 3/2 will probably be OK, and if not you can always rent a suit from one of the local dive ops.
Off Kona you can also run into cold spots. These are due to the fact that fresh water runs off the island not in rivers but by percolating down through the porous lava rock and upwelling as cold springs off shore. I've hit some very cold spring water on dives that made me glad I had the 5mm.
However, if you are going to just do a few dives over the week the 3/2 will probably be OK, and if not you can always rent a suit from one of the local dive ops.