When you go aground, first ensure your crew and boat are sound. Then determine what’s underneath the boat. If you’re on rocks and didn’t hole your boat, you might if you try to move it. Calling a professional may be your best bet. On a soft bottom, however, you can try to free your boat by kedging off.
Kedging means setting an anchor in deeper water and pulling the boat toward it, either mechanically or by hand. A winch or windlass makes this maneuver easier.
The anchor may be floated out on life preservers, carried out by wading or taken in a dinghy. When using a dinghy, wear PFDs, make the bitter end fast to the stranded vessel and put the rode in the dinghy. Pay out the rode while moving into deeper water to set the anchor.
Before kedging, determine which part of the boat would be easiest to free and where the deeper water lies. If the bow is grounded on the edge of a shoal, kedging to the opposite side of the bow can swing the bow around and free it from the bottom.
If the bow is grounded head on, kedging off the stern while attempting to back the boat by applying slow, steady power might help as long as you’re sure your propeller and rudder can move freely. Try applying power and rocking the boat while pulling on the rode. Just make sure the rode doesn’t foul the prop.
On a sailboat, you can rig a line from high on the mast to an anchor set off the beam. (A spinnaker halyard’s swivel fitting works well for this.) Pulling from a high spot may tip the boat enough to free it from the bottom. Just don’t put too much strain on the line; you don’t want to damage the rigging or jam the block at the masthead.
If all else fails, call for professional help to free your boat safely.
To learn more about boat handling and dealing with adverse conditions, take the Powerboat Handling seminar or the Seamanship course at a squadron near you.