He works as a captain of a submarine.

He practices every day to improve his sailing skills.

We plan to sail on a yacht during the summer vacation.

A nuclear submarine can travel underwater for a long time.

He always tries to act with caution.

He always acts carefully.

The submarine navigated carefully to avoid the underwater mines.

He always changes the topic to avoid the problem.

He always changes the topic to avoid the problem.

He loves to dive into the sea.