Check My Plotting...
While it''s important to know how you got to 133.66, compasses are graduated in 5 degree increments. And while large ships with powerful autopilots may be able to hold a heading within 5 degrees, sailboats can''t. Offshore, between large swells and wind gusts/lulls & shifts, I think holding a heading within 20-30 degrees is reasonable. After all, sailing is a fluid environment.