Bermuda is a small island and benefits from near-complete wireless coverage. One:Connect (formerly CW Bermuda) and CellOne (Bermuda Digital Communications) are the two operators providing LTE and 4G service across the island.
Hamilton, the capital, has the strongest signal. The South Shore beaches including Horseshoe Bay, Jobson's Cove, and Elbow Beach have solid 4G. The Royal Naval Dockyard on the west end is well covered. St. George's Town on the east end, the ferry routes across the Great Sound, and the railway trail all have reliable coverage.
Bermuda's small size means there are very few dead zones. The only places with weaker signal are within some limestone cave systems (the Crystal Caves attract many visitors) and occasionally on the water between ferry stops. For most activities on the island, 4G data is consistently available. Average speeds run 20 to 50 Mbps across the island.