(b) Factors to be considered, as a minimum, include:

1. (1) Location of the obstruction in relation to the navigable channel and other navigational traffic patterns.
2. (2) Navigational difficulty in the vicinity of the obstruction.
3. (3) Clearance or depth of water over the obstruction, fluctuation of water level, and other hydraulic characteristics in the vicinity.
4. (4) Type and density of commercial and recreational vessel traffic, or other marine activity, in the vicinity of the obstruction.
5. (5) Physical characteristics of the obstruction, including cargo, if any.
6. (6) Possible movement of the obstruction.
7. (7) Location of the obstruction in relation to existing aids to navigation.
8. (8) Prevailing and historical weather conditions.
9. (9) Length of time the obstruction has been in existence.
10. (10) History of vessel accidents involving the obstruction.