46 CFR 401.450: Pilot change points.

A Registered Pilot's assignment is completed when the vessel to which they are assigned completes its arrival at or, in the case of a through trip, passes any of the following places:

(a) Snell Lock;

(b) Iroquois Lock, Ogdensburg, NY;

(c) Cape Vincent;

(d) Port Weller;

(e) Port Colborne;

(f) Detroit/Windsor, other than assignments originating or terminating at a point on the Detroit River;

(g) Port Huron/Sarnia;

(h) Detour;

(i) Buoy 33, St. Marys River, Point Iroquois;

(j) Chicago with respect to assignments originating at Detour or Port Huron/Sarnia; and

(k) Duluth/Superior and Fort William/Port Arthur with respect to assignments originating at Buoy 33.