Paragraph- Sent 1: On a nice and sunny day, Bob and Sally walked to the beach.
Sent  2: When they got there, the first thing they wanted to do was to look for buried treasure.
Sent  3: To find the treasure they had brought two shovels and two buckets.
Sent  4: They both started digging holes in the sand with their shovels.
Sent  5: After looking very hard for treasure for an hour, they didn't find anything.
Sent  6: This made Bob and Sally very sad.
Sent  7: They gave up and went to play in the water.
Sent  8: While they were playing in the water, Sally found a bottle with a little paper inside.
Sent  9: Sally opened the bottle and found a treasure map.
Sent  10: Sally showed the map to Bob and they started to look for the treasure.
Sent  11: After walking every step that the map said, they started digging with their shovels.
Sent  12: After digging a really a big hole, they found a box.
Sent  13: They were very happy that they found it and wanted to see what was inside.
Sent  14: Bob slowly opened the box and there was a very big pearl.
Sent  15: Next, they ran to a special store to ask about the pearl.
Sent  16: The worker in the store told Bob and Sally that the pearl could make them rich.
Sent  17: Bob and Sally looked at each other and decided not to sell it.
Sent  18: They took the pearl home and saved it in a special box, so they could remember their day at the beach.? 
Question: How long did Bob and Sally look for treasure before going to play in the water?
No.