re: Grand Isle Navigational Hazards

I'd say don't go on the front side of the beach with your skiff unless it's absolute glass out there. Even then, bring a good anchor and chain, and don't get too close to the surf. People sink or beach their little 16' bass boats in the surf all the time. Also, the two passes on either side of the island have very strong currents, so just be careful there as well.

Edit: I just read the part about fishing Fourchon. Same rules apply about the pass and the beach. You can easily fish the marsh on either side of Fourchon with a small aluminum boat or skiff. If you try to run West on the the back side towards Timbalier, beware that there's dredge lines and rock piles just under the water that can bust your prop, so don't cross any warning signs