Speed, to judge:
If you have no log, you can by practice get so that you can gauge a boat’s speed within a half knot by watching the water. When running along shore, make a practice of timing the boat between measured points. By doing this constantly you will get so experienced that you can judge by eye very close to the speed she is making. Another way is to time her as she passes floating objects, or while passing a stick dropped over from the bow, count the seconds one, two, three, and so on, until it passes the stern. Knowing the length of the boat by this means you can roughly estimate her speed through the water. If your boat is 25 feet long, and it takes her 5 seconds to pass an object, she is making about 3 knots.