The Maritime flag for Twenty One

The Maritime Flag for Twenty-Two

This flag is loosely based upon the ICS flag for number two, but the colours are reversed and two extra dots are present.
The Maritime Flag for Twenty-Three

Originally France holds the ICS pattern for three, but for twenty-three Russia gets respects, or its Serbia? I guess it's whatever you want.
The Maritime Flag for Twenty-Four

Again this is based on the number fourteen, which is derivative of the ICS flag for four and NATO flag for four.
The Maritime Flag for Twenty-Five

Just as twenty-five has an un-noticed symmetry like 69, this flag is geometrically symmetrical.
The Maritime Flag for Twenty-Six

The Maritime Flag for Twenty-Seven

The Maritime Flag for Twenty-Eight

The Maritime Flag for Twenty-Nine
