Maritime Numeral Pennants: Digits 0–9

Key facts and distinctions

Article focus: International Code of Signals
Learning distinction: Sign, message and context are separate
Numbers: Points 0 to 9
Number: Ten number pennants
Message 0: Number 0
Messages 1 to 3: Points 1, 2 and 3
Messages 4 to 6: Points 4, 5 and 6
Messages 7 to 9: Points 7, 8 and 9
R with numerals: Distance in nautical miles
S with numerals: Speed in knots
Decimal signs: Answer pennants between digits
Total set of flags: 40 characters including letters and special characters

Ten different digits, a set of characters of its own

The International Signal Book distinguishes 26 letter flags, ten pennants, three assistants and the answer pennant. This results in a total of 40 characters of the complete flag set. The numeral pennants individually represent the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Zero is explicitly one of them and is not a sign of a missing message.

The numerical pennants shown here each have their own color and surface pattern. Their slender shape distinguishes them as a group from the predominantly rectangular letter flags. When learning, however, not only form categories should be queried: It is crucial to assign each pennant to its digit. Two characters can contain similar colors and yet clearly differ by their arrangement and additional geometric features.

A number needs the appropriate meaning and unity

Figures alone do not yet say what is counted or measured. The signal book therefore uses defined relationships. For example, R with one or more digits denotes a distance in nautical miles; S with digits denotes a speed in knots. V with numerals, on the other hand, stands for speed in kilometers per hour. The preceding letter and the unit are therefore as important for understanding as the number itself.

Other additions concern date, coordinates or time. This is a reason not to guess any group of numbers from their individual parts. For certain groups, supplementary digits also change the variant of a message or provide a more detailed response. The common denominator remains: numbers are structured additional information. They get their role through the group defined in the signal book and not through a freely invented everyday association to the pennant image.

Repetitions, decimal signs and sports use

For duplicate digits, the code provides for assistants if there is only one set of each character. The official example 1100 can be represented with the pennant 1, first auxiliary stand, pennant 0 and third auxiliary stand. The third auxiliary stand in this case refers to the third numerical position at which the zero stands. An assistant therefore does not carry a fixed digit, but takes its meaning from the respective group.

The answer pennant can represent a decimal between digits. When determining an assistant, he does not count as an additional numerical position in this function. In addition, the sailing sport uses number pennants within its own signal system, for example in connection with a start shift. These sporting advertisements are read according to the race rules. Their existence does not alter the basic function of the ten digits in the International Signal Book.

Details Worth Remembering

Zero is a complete sign

Without its own zero pennant, numerous figures could not be clearly represented. When learning images, the zero therefore deserves the same place as the other nine digits. It denotes a numerical value and not a mere pause between other signs.

Number and unity learning together

A numerical sequence can look very accurate and still remain incomprehensible as long as the reference is missing. The various speed specifications with S and V make this clear: Only the defined addition clarifies which unit belongs to the number.

1100 explains repetition

The example from the official signal book shows two different assistants within a number. The first repeats the first one, the third the third numerical position with the zero. The order explains the function better than an isolated image of the stander.