I have a 17.5 foot 1994 Sea Nymph Aluminum Boat. I esitimate total weight with gear to be 1,500 pounds to 1,800 pounds. I just bought the boat and am purchasing anchors. Most of the time, I will be in Spring Lake, Michigan where wind can be a slight factor but nothing is too crazy. For Spring Lake, I'll be fishing and swimming with my kids....I'd like to get two anchors (1) 22 lb Minn Kota Crab Clab and (2) a (20 or 30 lb ) River Anchor. The dealer recommended 18 pound River Anchor. What are your thoughts? Is 30 too heavy or is 20 fine (as long as I have enough chain and rode ). Appreciate you weighing in..haha! One more thing...I'll be getting a Guardian FX-7 w/ 150 foot of rode and 10' of chain for Lake Michigan and when I really need to tie-up. Thanks. Doug -