On our recent visit to Botswana we aranged to stay with a friend of a friend in Francistown, the mining center in the northern part of the country.  Charles Byron, our host, met us in town and led us out to the farm he and his wife owned, about 10 km NW of the city center.  As we were pulling in past the house, we noticed a 2-seat kayak on the lawn - an old, faded kayak, orange on top and white on the bottom.  Memories started churning , but our attention was diverted by unpacking and being handed a welcoming glass of wine.  The next day, however, Tom was able to ask our host about the kayak and where he had gotten it. Turns out that when the local office of Falconbridge Explorations was closing, Charles put in a bid and ended up getting all the company's files.  While collecting this windfall, he happened to notice the prow of a kayak sticking out of a dumpster outside the office (not an everyday occurrence on the edge of the Kalahari).  In response to his questions, he learned that the kayak had been lying around the office for years, that it was still in good condition but wasn't worth the cost of shipping back to the home office, and that he could have it if he wanted.  So it ended up at his place where family and friends used it to challenge the nearby river when it was in flood.

With a chuckle, Tom informed his host that he had purchased that very same kayak nearly 30 years before as a diamond exploration tool.

Back in 1976-77, Tom worked as a field geologist for Falconbridge Explorations (Botswana) Ltd.  The company had just flown an aerial magnetic survey of its prospect area in the north-central part of the country and detected a number of "paired bullseye" anomalies in the area east of the Makgadikgadi Pans.  In this part of Africa, patterns like that mean kimberlite pipes - and diamonds.  

The next step was to confirm the size, shape, and intensity of the magnetic anomalies with a higher resolution ground-based survey.  This involved identifying the approximate location of the bulls-eye anomaly on air photos, and establishing a survey grid on the ground .   For the largest and most attractive of the anomalies, the grid extended from the shoreline on the northeastern margin of Sua Pan out across a small [dry] embayment.  The grid  was marked out by meter-long stakes cut from the local mopane scrub and hammered into the ground every 50 meters along a grid line.  This particular grid took a week or more for the crew to survey and put all the stakes in - then it was time to head into town for payday and re-supply.  It was March, and while we were in town the rains came - lots of rain.

By the time we were able to get back out to camp, the Semowane River had come down in flood, and the little embayment had over a meter of water in it.  We stood on the shore line and gazed at all the mopane stakes floating in the breeze.  So, here's a problem; the most significant target of the lot, and no way to collect meaningful data until the next dry season - months away.  That was when Tom had a flash of inspiration.  In the window of Haskins' hardware store in Francistown was a 2-person kayak, intended for local anglers to use on the nearby reservoir.    He got on the radio phone to Johannesburg and "floated" his idea by the chief geologist.  Would he be willing to authorize a 200 Rand (about US$270) purchase on the possibility of getting the desired information in the next few days?  It was actually a no-brainer; the cost of the kayak was less than the cost of keeping the exploration camp in the bush for one day.

Thus, bright and early the next day Deb and I strapped a shiny new kayak to the roof rack of our Land Rover and headed off to the pans.  The plan was for Deb to sit in the front cockpit with the magnetometer, set on automatic recycle, nestled between her feet.  As each number came up she would record it on a notepad. Tom would sit in the back and attempt to paddle a straight line at a constant speed against a stiff cross wind.  To give us a visible target to aim for, we parked a truck on each side of the embayment at the point where the surveyed grid lines intersected the shore.  And then it was off - heavy aerobics in the rear seat and studied concentration in the front.  Back and forth, ten lines, twelve, done.  Returning to camp, Tom transfered the magnetometer readings to the base chart of the grid - spreading the data points evenly along each line.  The resulting contours showed an absolutely beautiful double bulls-eye, in gloroius resolution.  Two days later the data was in the hands of the company's geophysicist, and in a month we had a drill rig on site.

In the end it wasn't clear what we had found, though the suspicion was that we had encountered a carbonatite pipe rather than kimberlite [carbonatites are an unusual igneous form of calcium carbonate found in association with deep crustal rifts].  However, the concept of kayak-borne surveys had been proven successful.