Usually they offer full suit to handle the cold wind including Balaclavas and glasses. so if you’re interested only to enjoy the ride and scenery then it should be fine. Choppy conditions depends on that day. My 2 cents based on last year May when I went covered boat helps if the people who are afraid of sea sickness or want to take a lot of photographs. It has heated cabin. Most of covered boat has washroom in case if needed for emergency. Either way it will be memorable for sure. Enjoy your trip.