RedactedNarrative: V1 was at anchor while occupants fished.  Anchor line was attached to bow in choppy conditions for approximately 45 minutes.  Occupants observed water in splash well for most of that time.  O1 observed the stern low in water and switched the bilge pump from "auto" to "on."  Occupant observed the bilge pump start pumping.  O1 then started motor and began bringing in lines and the anchor.  V1 leaned to port taking water over the port stern flooding the cockpit.  V1 immediately rolled to port and capsized, ejecting all occupants.  V1 remained floating upside down,  A passing vessel observed them in the water and picked them up.  V1 was recovered the next day in the same condition.