The Night Heron family of kayaks, which includes the Petrels, grew out of the Guillemot family of designs as I started venturing out in to rougher conditions. The Greenland Inuit influence is more explicitly evident with sharper, more angular end shapes, lower back decks and more steeply raked cockpit.
The Night Heron family differs from traditional Inuit designs by maintaining a full waterline shape out to the ends instead of the "pinched" ends that are characteristic of the skin on frame kayaks made by the Greenlanders. The fuller ends create a long effective waterline giving the Night Heron good efficiency at high speeds. The volume distribution results in a boat that surfs very easily. This is further helped by a chine that starts up soft near the bow and hardens up at the cockpit and behind.
Although the beauty of the Night Heron shape has received attention outside of the kayak world, it is really on the water that the beauty of the design becomes most evident. These boats are fun to paddle.