USCG Heartland District | Midpage80.805Rock Island, FL to Cape San Blas, FL.80.810Cape San Blas, FL to Perdido Bay, FL.80.815Mobile Bay, AL to the Chandeleur Islands, LA.80.825Mississippi Passes, LA.80.830Mississippi Passes, LA to Point Au Fer, LA.80.835Point Au Fer, LA to Calcasieu Pass, LA.80.840Sabine Pass, TX to Galveston, TX.80.845Galveston, TX to Freeport, TX.80.850Brazos River, TX to the Rio Grande, TX.