A UK flagged vessel should fly the Red Ensign during daylight. It must be worn when entering a foreign port. They are not worn while racing. The ensign should be flown from the stern of the vessel.
The size of the flag should look appropriate for the boat. An approximate guide often used is 1 inch per foot of vessel or follow the guide below:
3/4 Yard = 20 - 26 ft.
1 yard = 27 - 34 ft
1 1/4 yard = 35 - 42 ft
1 1/2 yard = 43 - 50 ft
1 3/4 yard = 51 - 60 ft
The size of the flag should look appropriate for the boat. An approximate guide often used is 1 inch per foot of vessel or follow the guide below:
3/4 Yard = 20 - 26 ft.
1 yard = 27 - 34 ft
1 1/4 yard = 35 - 42 ft
1 1/2 yard = 43 - 50 ft
1 3/4 yard = 51 - 60 ft