Those are very good questions, Fred.

There is almost always a current through the bridge, but it is not tidal, it is wind-driven, so it stays the same direction for days at a time. If it is going north, you won't have to worry about the bridge. If it is going south, there is a big open area right before the bridge, with mangroves all around it. You just snuggle your boat up to the mangroves and hang on until the bridge opens.

Now, if the current is going north and the wind is out of the south/southwest as predicted, you might have trouble getting through the bridge against the current, so bring a crew and a paddle -- or hitch a tow from a powerboat.

For a distance race it is always a good idea to bring an anchor.