Motor sailed from Channel Co 4 Cay to Royal Island anchorage Eluthera. Left at first light. Flat out of cut. 3 to 4 swell with big interval no wind almost like a pond. Jim took off Bob did about 7kn we were around 6kn. Heard a thump, bang on hull and speed dropped 1/2 knot. after contacting Bob he said I needed to go take a look so stripped down mask and fins wiggle onto swim deck and took a look. Kelp wrapped in some sort of plastic bag had stuck to rudder and all over prop. undid and all was good. 14 thousand feed was the depth super gin clean water wow. Asshole about the size of a BB. Caught first fish. Barracuda on Green Lure. Talked with Sunshine another boat and had a freighter just miss us. what a day.