33 CFR 161.10: Services.

To enhance navigation and vessel safety, and to protect the marine environment, a VTS may issue advisories, or respond to vessel requests for information, on reported conditions within the VTS area, such as:

(a) Hazardous conditions or circumstances;

(b) Vessel congestion;

(c) Traffic density;

(d) Environmental conditions;

(e) Aids to navigation status;

(f) Anticipated vessel encounters;

(g) Another vessel's name, type, position, hazardous vessel operating conditions, if applicable, and intended navigation movements, as reported;

(h) Temporary measures in effect;

(i) A description of local harbor operations and conditions, such as ferry routes, dredging, and so forth;

(j) Anchorage availability; or

(k) Other information or special circumstances.