Ranges and Transits

Perhaps you have at one time or another used a navigational range for going up a channel. A "Range" is simply lining up two non-moving points and keeping them lined up as you cruise up the channel. Government ranges are marked on the charts and the closest range marker will be shorter than the one farther behind it.

But, other than these obvious ranges, there are others that you can use on your own. Here are some good examples:
1) If you are navigating across a body of water with a side current, you might pick out a point (say a tree, for example) to steer toward. But, you should also pick out another point beyond that tree and use it as a range, keeping them lined up. If you didn't pick out a back point to make the range, you might keep the bow right on the closest tree and it would appear you are on course. However, you might be getting swept way off course. With the range, you would immediately know you were being set to one side or the other. You need to keep both points of the range lined up.

2) You anchor your boat and think everything is set. It doesn't appear that you are moving. But, the best way to be sure is to find a range. Pick out a point (another tree, perhaps) and another stationary object behind it. If they do not stay lined up, your anchor is not holding.

3) You are cruising along and see a boat approaching at 90-degree angles from your right, making it the right-of-way boat. Here is a great and easy way to assess an upcoming problem.., and it really is valuable for sailboat racing. Look at the boat and then its relation to the background.

A. If the boat appears to be going faster than the background, it will pass in front of you.

B. If the boat appears to be going slower than the background, you will pass in front of it.

C. If the boat appears to be going the same speed as the background, you are on a collision course and you must take action.