I used to boat alot on the Columbia river in Portland Or. A deep water river with large ship traffic. The only way your gonna hold on during a 4 foot swell is to use a VERY heavy Anchor, a 20ft heavy chain after that then what is a big bungy cord in between that stuff and your boat. Then you will need to anchor nose out and up river and use a long stern line to figure out how to get the back of the boat to shore. I had a 21ft sport boat nearly beached one day when I failed to push it out when the first hints of the big waves show up.
Still risky. . . .Get your self some Deck bait and let here hold the fort while you are in the woods.
