Always insist on having your fellow boaters install air bags (flotation). If they come out of their boat, the boat will hold far less water and is easier to manipulate. If possible, try twisting the boat so the cockpit (or open portion) is upside down or facing downstream. This will take a great deal of water pressure off the boat. Where it is feasible, work with the existing current. On end to end pins, one end may be easier to pull or push. Small movements can unbalance this type of pin and allow the boat to release and head downstream. When stuck in a sieve and some vertical pins, you may need to back out the same way you entered the pin. Once the lower end is free, you may be able to lift it over the obstruction and let gravity and current assist you.