It was a small boat. I think of a pair of them. Yellow stacks. A speedgun measures speed. His could measure down to 1mph which works for our hobby.
Are those Kotori87's boats you're talking about? I wasn't at Nats (I'm a big gunner) but I know Kotori uploaded some gopro footage of the event. Also I don't remember seeing anything with yellow funnels besides these:
1 mph doesn't work for our hobby. 1mph is ~1.47 ft/s A 24sec ship goes ~4.17 ft/s or about 2.8 mph A 26sec ship goes ~3.85 ft/s or about 2.6 mph You'd probably need something with sensitivity in the 0.05 mph range or lower to get close enough that it might be worthwhile.
It was the Stalker Pro 2. Gascan got it to help speed checking at a small local pond. Other radar guns are available, but are not able to read accurately at the low speeds we need. He also printed out a table with the speed chart, converting all of the relevant speeds into MPH and KPH. It is also useful for Big Gun, since their speed chart works out almost exactly to 1 knot (scale) = 0.1kph (on the radar gun). Very convenient and easy to read
