Within three miles of the Alaska coastline, visible emissions, excluding condensed water vapor, may not reduce visibility through the exhaust effluent of a marine vessel by more than 20 percent except as follows:

1. (1) while at berth or at anchor, visibility may be reduced by up to 100 percent for periods aggregating no more than

   1. (A) three minutes in any one hour; and
   2. (B) an additional three minutes during initial startup of a vessel; for purposes of this subparagraph, "initial startup" includes the period during which a vessel is testing equipment in preparation to casting off or weighing anchor;

2. (2) during the hour immediately after weighing anchor or casting off, visibility may be reduced under one, but not both, of the following options:

   1. (A) visibility may be reduced by up to 40 percent for that entire hour; or
   2. (B) visibility may be reduced by up to 100 percent for periods aggregating no more than nine minutes during that hour;

3. (3) during the hour immediately before the completion of all maneuvers to anchor or make fast to the shore, visibility may be reduced under one, but not both, of the following options:

   1. (A) visibility may be reduced by up to 40 percent for that entire hour; or
   2. (B) visibility may be reduced by up to 100 percent for periods aggregating no more than nine minutes during that hour; and
4. (4) at any time not covered by (1) - (3) of this section, visibility may be reduced by up to 100 percent for periods aggregating no more than three minutes in any one hour.

(Eff. 1/18/97, Register 141; am 6/21/98, Register 146)

Authority: AS 46.03.020, AS 46.14.030