Several times the men go swimming completely naked and we see full nudity from behind as they dive into the water. But with No sexual content.

Blasphemy. God is used a few times. Milder profanity. Sh*t. Also, discussing of going to the bathroom outdoors and what to use for toilet paper.

Smoking of pipes.

Several times the boat is in jeopardy as it takes on storms and white water. Arguing among the participants and a couple of times life is on the line.