46 CFR §108.241

1. (a)Each helicopter deck must—
   1. (1)Have a wind direction indicator located in an unobstructed area readily visible to helicopter pilots approaching the deck;
   2. (2)Be fitted around the perimeter with yellow and blue lights in alternate order, not more than 3 meters (10 ft.) apart; and
   3. (3)Be marked with—
      1. (i)The unit's identification;
      2. (ii)A continuous line 40 centimeters (16 in.) wide on the perimeter; and
      3. (iii)Aiming circles as may be appropriate considering deck configuration, helicopter type, and operational requirements.
2. (b)All markings must be in a contrasting color to the surface of the deck.