Here's a short story:

When I was young,I liked to play jokes on people I knew, especially on my parents and friends. One day my mother was cooking and I was playing with my younger brother Tony. Suddenly I ran to my mother and said: "Tony fell from the open window!" She was very worried and ran out of the kitchen. Then I said: "Don't worry, I'm just joking." My mother shouted at me, "If you do it again, I'll hit you." Another day I went swimming with my friends in the sea. I wanted to play a joke on them. In the beginning I swam fast and I called out "Help!". All my friends came to help me. However, they found that I was joking. But half an hour later I wasn't joking. I was so fast, soon I got tired and couldn't swim on in water. I tried my best to call my friends for help, but this time nobody came to help me. In the end they found I was telling the truth. They came and saved my life. They took me to the hospital. This is the best lesson in my life. From then on I haven't joked on anyone. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: Does this person consider themself to be a joker?
Guess: not any more

Question: Was it because of a traumatic experience?
Guess: yes

Question: What happened?
Guess: couldn't swim

Question: Did he call for help?
Guess: yes

Question: Who did he call to?
Guess: his friends

Question: Could they hear him?
Guess: unknown

Question: Why didn't they come?
Guess: thought he was joking

Question: Why?
Guess: he always played jokes

Question: Did he call for help when he didn't need it?
Guess: yes

Now answer the following question in the same format.

Question: Where were they swimming?

in the sea