If you sprint/run until you're tired and then hop into a boat, you'll still be panting and breathing for the duration of the boat ride.
- Legacy ID
Run until tired/breathing and get in a boat.
The vehicles are powered by bicycle chain!!
The SAME heavy breathing bug occurs for helicopters in coop multiplayer.
I landed a helo and waited for 3 minutes on the ground and the heavy breathing stopped. But when I took off, the heavy breathing started again, and lasted the whole ride back to base.
Traveling in any vehicle must cause the ARMA3 engine to register a reaction like: "the player is moving quickly with a heavy backpack, so he MUST breath heavy now!!!".