🔍 Key Concepts

• International Code of Signals (ICS) and how letter–number groups are organized • How the ICS separates groups for bearings, positions, courses, and speeds • Using the signal groups table to see what the initial letter (A, B, etc.) stands for

💭 Think About

• Ask yourself: In the ICS, does a group starting with the letter A normally describe a direction, a vertical distance, underwater activity, or a rate? • Compare where bearings and speeds are found in the code – do they usually start with the same letter, or are they in different letter groups? • Think about whether diving would more likely have its own warning flags/signals rather than being coded as a number group like A243

✅ Before You Answer

• Look up the International Code of Signals index and find which subject category the letter "A" introduces • Confirm whether bearings are expressed in degrees and whether the ICS has a specific bearing signal group separate from altitude and speed • Verify if diving operations in the ICS are usually indicated by single-letter flags or letter–number groups like A243