Gary.
If you plan using that .22 in a boat, better use those Mustard seed shot. A fellow from where I used to work went fishing with a friend in a fair sized creek. A cottonmouth fell off a limb into the boat. The friend paniced and shot 4 holes in the bottom of the boat. The snake slipped out of the boat untouched leaving them with a sinking boat. With some fast paddling, they made it to the bank before the boat sunk.

Russ