OPOD - Bondi Beach Surf Bow

Bondi Beach Surf Bow ~ A momentary bow formed by wave flung spray appears to dwarf the two surfers further along the wave. Bondi Beach, famous for its surf, is near Sydney, Australia. Image taken by Geoff Clayton. ©Geoff Clayton, shown with permission

The bow's colours are more widely separated than usual because the spray droplets are smaller than raindrops. Smaller droplets give progressively wider and more pastel coloured bows. In the limit of mist droplets we have a fogbow.

Another effect that cannot be seen in the Bondi Beach bow is the effect of seawater. The dissolved salts increase the refractive index of seawater and its bows are therefore smaller than those produced by rain.

The relative size of rainbows and seabows is well shown in the very rare photograph at right taken aboard a tanker by J Dijkema. The upper bow was produced by rain and the smaller lower bow (by ~0.8° radius) is from Pacific Ocean spray.