Sections 10 to 14

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10. Screening of Sidelights

Diagram 1

* Individual screening arrangements described by the light manufacturer, that comply with the “cut off” specified in the Collision Regulations will be accepted.
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11. A Two Axis Goniometer

Diagram 2

12. Minimum Installation Height of Reflectors Above the Water and Corresponding Echoing Areas for Adequate Detection by Standard Shipboard Radars

Diagram 3 - Equivalent echoing area (square meter)

13. Typical Azimuthal Polar Diagram for a Radar Reflector

Diagram 4

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14. Vertical Separation of Masthead Lights

14.1 Collision Regulations Annex 1 paragraph 2(a)(ii)

WL is waterline with vessel on even keel. XZY is parallel to WL passing through the point P on the uppermost continuous deck, vertically below A. A is the foremast light; D is the mainmast light. It is required that ZD is at least 4.5 metres more than AP.

14.2 Collision Regulations Annex 1 paragraph 2(b)

1. To find the Angle C (with the aid of the Ships drawing)

   Horrizontal distance: CL + LH + HF = CF

   Vertical heights: DE + EF = DF

   Tan C = DF ÷ CF

2. To find BH (The height where the dotted line crosses the foremast)

   Tan C = BH ÷ CH

   ^BH = CH × Tan C

3. To find height of B above A (with the aid of the Ship’s drawing)

   AB = BH - AH

WL is waterline with maximum trim by the stern.
C is 1000 metres ahead of the vessel’s stem.
A is the foremast light; D is the mainmast light.
CD produced cuts the foremast at B; for the foremast light to be seen from C distinctly separate from and below the mainmast light, it must be placed a minimum distance of about 0.5m below B at position A.

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