I'd call 6 knots walking speed
7 knots is 7.7 mph.
From wiki: "Speed is another factor that distinguishes walking from running. Although walking speeds can vary greatly depending on many factors such as height, weight, age, terrain, surface, load, culture, effort, and fitness, the average human walking speed at crosswalks is about 5.0 kilometres per hour (km/h), or about 1.4 meters per second (m/s), or about 3.1 miles per hour (mph). Specific studies have found pedestrian walking speeds at crosswalks ranging from 4.51 kilometres per hour (2.80 mph) to 4.75 kilometres per hour (2.95 mph) for older individuals and from 5.32 kilometres per hour (3.31 mph) to 5.43 kilometres per hour (3.37 mph) for younger individuals; a brisk walking speed can be around 6.5 kilometres per hour (4.0 mph). In Japan, the standard measure for walking distance is 80 meters for 1 minute of walking time or 4.8km/h. Champion racewalkers can average more than 14 kilometres per hour (8.7 mph) over a distance of 20 kilometres (12 mi)"
Clearly you have never entered 10 k events or you'd know that 7.7 is a very brisk walk to say the least. From Runner's World: "Now, all that said, here is a general guideline on treadmill speeds: for most people 2 to 4 mph will be a walking speed; 4 to 5 mph will be a very fast walk or jog; and anything over 5 mph will be jogging or running."