Can I use an alternating Red & Yellow Strobe light as my safety light?

The Ops Policy Manual authorizes use of the public safety vessel ID light for Aux vessel facilities. Though no specific type (rotating or strobe) is designated, as long as a strobe light meets the Nav Rules requirement (alternating red & yellow flashing light at regular intervals of 120 flashes or more per minute) you can use a strobe.

Applicable Nav Rules:

Lights which may be displayed for public safety activities are clearly defined in Annex V of the Inland Navigation Rules (33 CFR 88.12)

§ 88.12 Public Safety Activities
   (a) Vessels engaged in government sanctioned public safety activities, and commercial vessels performing similar functions, may display an alternately flashing red and yellow light signal. This identification light signal must be located so that it does not interfere with the visibility of the vessel's navigation lights. The identification light signal may be used only as an identification signal and conveys no special privilege. Vessels using the identification light signal during public safety activities must abide by the Inland Navigation Rules, and must not presume that the light or the exigency gives them precedence or right of way.
   (b) Public safety activities include but are not limited to patrolling marine parades, regattas, or special water celebrations; traffic control; salvage; firefighting; medical assistance; assisting disabled vessels; and search and rescue.

The use of "strobe lights" is also addressed in the Navigation Rules, which prohibits their use as a "signal to attract attention".  COLREG Rule 36 states:

If necessary to attract the attention of another vessel, any vessel may make light or sound signals that cannot be mistaken for any signal authorized elsewhere in these Rules, or may direct the beam of her searchlight in the direction of the danger, in such a way as not to embarrass any vessel.  Any light to attract the attention of another vessel shall be such that it cannot be mistaken for any aid to navigation. For the purpose of this Rule the use of high intensity intermittent or revolving lights, such as strobe lights, shall be avoided.

Inland Navigation Rule 36 omits the last sentence of COLREG Rule 36 (i.e. strobe lights), because, Inland Navigation Rule 37 allows for the use of a "high intensity white light flashing at regular intervals from 50 to 70 times per minute" (i.e. strobe light) as a distress signal.  This being the case, any other uses of a such a light could be mistaken as a distress signal, thus contrary to COLREG/Inland Rule 36.