Objects in the image:
category: surfboard
category: person
category: person
category: surfboard
category: boat

Guessing-game dialogue about one of the objects:
q: is it a person?
a: No
q: is it the boat?
a: No
q: is it water?
a: No
q: is it apart of the boat?
a: No
q: is it sky?
a: No
q: is it a wave?
a: No
q: is it something on the boat?
a: No
q: is it alive?
a: No
q: is it a sail?
a: No
q: Is it in the upper half of the picture?
a: No
q: is it in the lower half of the picture?
a: Yes
q: is it on the right half  of the picture?
a: Yes
q: is it sand?
a: No
q: is it white?
a: No
q: is it a clothing?
a: No
q: is it near to the swimming person?
a: Yes
q: is it foam?
a: Yes