Range and arc of visibility of lights on basis of length of vessel ?

1
FOLLOW

Masthead light – 225 – 22.5, Sidelight 112.5 – 22.5, Stern light 135 and 67.5, in a vsl of less than 20 mtrs sidelights may be combined.  
Range: Vsl > than 50 mtrs Masthead 6 miles, Rest all lights 3 miles.
Vessel > 12mtrs but less than 50 mtrs Masthead 5 miles (vsel > than 12 mtrs but , than 20 mtrs masthead 3 miles) rest all 2 miles
Vsl < than 12 mtrs: Masthead 2 miles, sidelights 1 miles and rest all 2 miles.