It flooded in Houston, Texas and these guys were rowing an inflatable pool

It would be more dangerous if they were in a flooded house. But thats assuming this is an escape to higher ground. If this was just for fun it was definitely dangerous. There are countless snakes in that water, not to mention alligators

Also diseases and parasites, not to mention medical waste and some other types of waste. sharp objects like knives, broken glass, pending on how deep cars

Falling out and getting snagged up on submerged debris or the pool get a leak and you are really screwed. Just an all around bad udea unless an emergency evacuation

If that was the case they would have brought at least a few necessities like clothes