Hey Luke - there are a lot of factors that will influence the survey time. Are they searching with dogs? What is the terrain like (steep incline, heavy brush, rocky, muddy), what's the weather, etc. How far apart are the transects? It is a team of people or an individual? If you can account for those factors, I've seen estimated normal walking time to be about 1.4 meters/second or 3.1 miles per hour. For someone doing a search operation I would probably lower that to maybe 1m/sec or 3 mph for an estimate.