Post History
To expand on an earlier answer, and what the OP himself mentions, I will add a few more elements. First, the count of persons on the trip. The rescuers need to know when they are done. If they'v...
Answer
To expand on an earlier answer, and what the OP himself mentions, I will add a few more elements. First, the count of persons on the trip. The rescuers need to know when they are done. If they'v...