Map for Chandeleur Islands

Planning a trip and will be my second time going out to Chandy using the little skiffs without electronics (depth finder, GPS). The first trip was great and we caught plenty of fish but I didn’t love flying blind. Learned a lot and I’d love to carry that knowledge forward to this trip. Wanting to do some map study and bring a handheld GPS (or cell phone?) to mark guts, bars, grass flats, etc.

Have any of you done this or have any tips for using tools on the water to maximize the experience?

Edit: For those commenting on safety aspect, we'll be staying on a houseboat just off the island and using their "little skiffs". Not making the run to Chandy from MS or LA coast.