Lifesavers put up flags on the beach to show where it is safe to swim. The yellow and red flags are a national symbol of where lifesavers would like you to stay, so you don’t get caught in a rip. Rips are where water is quiet on the top but a dangerous current is dragging you out from underneath. The flags mark the area where it is safe to swim.
Please note that the dimensions listed on this website are for the overall print size - which excludes the frame and the matboard.