33 CFR § 64.31 - Determination of hazard to navigation.
In determining whether an obstruction is a hazard to navigation for the purposes of marking, the District Commander considers, but is not limited to, the following factors:
(a) Location of the obstruction in relation to the navigable channel and other navigational traffic patterns;
(b) Navigational difficulty in the vicinity of the obstruction;
(c) Depth of water over the obstruction, fluctuation of the water level, and other hydrologic characteristics in the area;
(d) Draft, type, and density of vessel traffic or other marine activity in the vicinity of the obstruction;
(e) Physical characteristics of the obstruction;
(f) Possible movement of the obstruction;
(g) Location of the obstruction in relation to other obstructions or aids to navigation;
(h) Prevailing and historical weather conditions;
(i) Length of time that the obstruction has been in existence;
(j) History of vessel incidents involving the obstruction; and
(k) Whether the obstruction is defined as a hazard to navigation under other statutes or regulations.