Oil Identification Codes

There are five primary codes that are used to represent oil colors on water. Similarly, there are codes used to represent the structure or distribution of oil on water. Use of the codes and terminology presented in this Job Aid will promote consistency among observers nationwide.

Oil Color Codes

Common Descriptors	Code
Silver Sheen	S
Rainbow	R
Metallic	M
Transition	T
Dark	D

Note that the oil color codes use single-letter capital letters.

Oil Structure / Distribution Codes

Common Descriptors	Code
Streamers	st
Convergence Line	co
Windrows	wr
Patches	pa
Tarballs	tb
No Structure (random eddies or swirls)	ns

Note that the codes for oil structure/distribution use two lower-case letters.