You might try a power boat cover for a slightly longer boat, like maybe 16'. They are less than $100.
Folgers plastic coffee cans work well for oarlocks as well.recycled vinyl billboard covers + a DIY grommet kit, an inexpensive rope threaded through, and cut up gatorate bottles or something of the like to cover your oarlocks so they don't poke through. Maybe not the best solution for the PNW (traps in moisture, pools rain water) but works well in a desert environment.
Or go full in and get an over it raft cover