English to Spanish Tech/Engineering Ships, Sailing, Maritime Naval Form Terminology

Hello everyone,

Context: The name of the form is LOG-NAVIGATION DATA SHEET. It can even be downloaded empty on pdf from google. In the one I have, the information for a ship´s journey is filled in. There are many terms here I cannot find in my dictionaries.

The term:
In one column, this is written.
"GYRO CRS/BRG"

Gyro is short for Gyroscope, and I understand it is used to measure location. The only logically related acronym I found for CRS was COORDINATE REFERENCE SYSTEM. I could find nothing for BRG that resembles this context (nautical).

Under the "GYRO CRS/BRG" column, every single space is filled in with an "M".

I would assume a lot of this naval vocabulary, is standardized. So...

My try:
"GIRO CRS/BRG"

Thank you for any help.