Nextel has intermintant service on Chincoteague Island. The closest iDEN tower is on Wallops, so sometimes you have service and sometimes you dont. Service is better on the bay side, however I have made clear DC calls from the Lighthouse trail on Assateague. The coverage map on the Sprint web site shows no Nextel service on Chincoteague, but it does work intermintantly.

I'm really surprised when I'm fishing for Tuna and I can make and receive calls. The nearest tower is at least 25 miles away in Chincoteague. Nothing in the way though... I guess that helps. Unfortunately my 7 year old phone is acting up. I'll be trading it in on a Motorola V60i (TDMA tri-mode) soon. Hope it works this well.