Bridge Height Finder

In May 2’s ‘Lectronic Latitude, reader Ron Taillon wondered if a device existed that would give a sailor approaching a bridge "a quick reading from the deck so you can have confidence in trusting the chart’s readings." We left it to you, our readers, to answer Ron’s question and boy did you. We were flooded with responses overwhelmingly recommending one device that can easily be bought at hardware stores or online.

"The obvious answer is a laser range finder," wrote physicist Jim Vickers. "You can range the top of your mast, then the bridge, and verify that the bridge is farther away than the top of your mast. They start at about $100 and are mostly used, by civilians at least, for measuring the distance to the pin on a golf green."

But our readers came through with other options for Ron:

• Beau Vrolyk — "There is a very effective low-tech solution called a bosun’s chair. You haul someone, preferably lightweight, to the masthead and they have a look. Works great, doesn’t break down, doesn’t cost much."
• Mike Stevens — "Mount a camera on your mast head (if you have a Raymarine CP this is simple to display at the helm). Or find a piece of driftwood — a fork or L-shaped six-ft piece is best — go aloft and lash it to the masthead in such a way as to extend forward and up like a bug’s feeler. It’ll hit before the mast."
• G. McBride — "To measure the hieght of the bottom of the bridge above the water, measure the angle with your sextant from a known distance from your intended position under the bridge, correct for your eye height above the water and solve the right triangle with the known length of the base and the sextant angle. Common knowledge before GPS."
• Doug Schenk — "If you’re sailing one-design, the test for the bridge height is the guy that goes before you!"

All jokes aside, approaching a bridge you’re unsure about can be a blood pressure-raising experience, but now you have all the options of doing so without gritting your teeth and popping a Toprol.