Drone search and rescue cover in Tavistock

Tavistock grew as a stannary town on the Tavy, and the open moor rises almost immediately to the east of it, ground that has been used for grazing sheep and ponies for centuries. Animals kept on that open ground don't respect a boundary the way livestock in a fenced field does, and a strayed flock or a scattered group of ponies can end up spread across a wide stretch of common in a single day, well beyond where anyone expected to look for them.

That same ground carries the legacy of centuries of mining, and the area is now recognised as part of the Cornwall and West Devon Mining World Heritage Site. Old shafts, adits and spoil heaps are scattered across the moor above the town, some grown over and easy to miss on foot until you're standing on the edge of one. Searching that ground on foot means moving carefully and slowly around hazards that don't always show up until close range, which is exactly the kind of ground worth checking from above first.

Tavistock gets wet weather from more than one side. The prevailing south-westerly pushes rain straight up the Tamar valley from the west, while Dartmoor does the same thing to Atlantic air on the town's eastern doorstep. Between the two, a dry search window can close faster here than the forecast suggests, and ground that was clear in the morning can be under low cloud by early afternoon.

That's where the two cameras earn their keep in different ways. The visual camera covers wide, open commons quickly in clear conditions, while the thermal camera picks out a warm body among bracken, gorse and long grass, ground where colour and shape alone make an animal, or a person, easy to walk straight past.

Tavistock Pannier Market and the remains of Tavistock Abbey sit right in the middle of town, both easy to use as a starting point when briefing before moving out onto higher ground. The River Tavy runs close by too, and works as a natural line to divide search areas either side of it.

From that centre, the ground changes quickly: open common and old mining ground rising to the east, and the Tamar valley falling away to the west towards Cornwall. Knowing which side of town a call has come from usually tells a coordinator straight away which kind of ground, and which kind of search, they're dealing with.

Tavistock sits on the road corridor linking Okehampton and Exeter through to Plymouth, so getting a launch point set up in the town itself rarely takes long, whatever the state of the moor above it. That same road puts Ivybridge and the moor's southern edge within reach too, useful if a search that starts around Tavistock needs to widen further south along the same range of high ground.