Real Florida experiences significant tide change. Does the GTA 6 map have changing tides? Big question. We hedge our bets.

Why it might exist

The storm imagery in trailer 2 shows the water level shifting. That implies there are dynamic water-level sim systems somewhere in the engine. Whether they go all the way to simulating a real tide cycle is another question.

If tides existed, they would affect how you get around canal-side, marina-side and Keys-side locations throughout the cycle.