RedactedNarrative: Operator stated he was at a "fast idle" moving from one fishing spot to the next when his engine struck a submerged stump and hooked onto the stump.  Operator tried to push the engine from the stump with push pole but as he walked to the transom, water came in over the transom.  Operator ran to the front to try to turn on bilge pump and he fell.  As the boat flooded with water and rolled over, Operator jumped overboard and swam to the stump.  He held onto the stump for 30-45 min until help arrived.