Could v/s be able to

[NGUYEN]

Dear Teacher:
Please help me with “could” v/s “be able to”. Please correct my sentences if necessary.
Two years ago, while trying to escape from the disaster zone, he faced a river. The bridge had been destroyed. He could not swim. He said to himself:
1. I wished I could swim.
2. I wished I were able to swim.
Thank you very much. Respectfully.
Nguyen

[Alan]

Both possible, but the first more natural.