A free knotmeter. Well, more precisely, it's
a chart that calculates the speed of an Alberg 30. If you throw one of those
stale saltine crackers that have been on the boat for three years off the bow
and time how long it takes to reach the stern, you can lookup on this chart
and determine the speed of the boat. Timing how long it takes to pass a
crab pot works just as well, if you've eaten all your saltines. I printed
a copy of this chart, folded it in half, trimmed it and laminated it for
durability on the boat.