Dynamic fin alignment system

A dynamic fin alignment system comprising:

• a bearing housing for attachment to a watercraft, the bearing housing having a housing bore with means for releasably securing a rotary bearing, the bearing housing having an interior base surface with a recessed slot defined therein, the recessed slot configured to releasably secure a correspondingly shaped changeable insert;
• a rotary bearing for being releasably secured into said bearing housing and having at least one race and a bearing bore coaxial with said housing bore when the dynamic fin alignment system is in an assembled condition;
• an axially symmetric body having a journal for cooperating with the at least one race to support rotation of the axially symmetric body relative to the rotary bearing;
• a fin extending from a first side of the axially symmetric body when the dynamic fin alignment system is in the assembled condition;
• a shear key extending from a second side of the axially symmetric body that is opposite the first side;
• and
• a plurality of said changeable inserts for being disposed, one at a time, within the recessed slot of the bearing housing, each changeable insert having a keyway for receiving the shear key when the dynamic fin alignment system is in the assembled condition.