A - Alpha

I have a diver down; keep well clear at slow speed. With three numerals, azimuth or bearing.

B - Bravo

I am taking in, or discharging, or carrying dangerous goods. (Originally used by the Royal Navy specifically for military explosives.)

C - Charlie

Affirmative.*

** With three numerals, course in degrees magnetic.

D - Delta

Keep clear of me; I am maneuvering with difficulty. With two, four, or six numerals, date.

H - Hotel

I have a pilot on board.

L - Lima

In harbor: The ship is under Quarantine.

At sea: You should stop your vessel instantly.

With four numerals, latitude. (The first two denote degrees and the rest minutes.)

N - November

Negative.*

Q - Quebec

My vessel is "healthy" and I request free pratique.

U - Uniform

You are running into danger.

Y - Yankee

I am dragging my anchor.