One of the nice perks about sailing on the Vision of the Seas is there is a beautiful dome covered pool. The sun will shine through no matter what the temperature is out to sea. If you have a balcony cabin, you can enjoy the fresh air from within your cabin even if it is cooler outdoors. Also, a great lounge for daytime viewing is either the Vicking Crown Lounge or the stern lounge which has the natuical name that I can't remember. Both have large glassed windows while being comfortably located inside. I believe your Hawaiian island weather will be great. The Pacific water can get a little rough during a crossing, but May/June is prime time for repositioning ships so it can't be all bad. My cousin just sailed on the Vision from Ensenada to Hawaii, and it was very cool and rough at sea. It was also cool & windy on Maui which put a damper on the Luau. Do indulge in at least one Helicoptor tour either over Volcano's National Park from Hilo or Waimea Canyon on Kauai. You will never forget it.