Made it under the bridge

[jlp0217]

I took delivery of my boat in Anacortes WA, July 22 2010 and was delivering to my slip in Tacoma Wa, with help from my broker, a licensed captian. Along the way we realized we didn't know what the air draft was, and couldn't find it in any of the paperwork. On the waterway in Tacoma, was the 11th street bridge, a lift bridge charted at 64ft MHW in the down position.
Using halyards, we attempted to measure the height of the mast, and came up with 65'. I don't remember if we just forgot to add from the deck to the water, or if we were just that far off. Anyway we came under the bridge on a 7' tide with MHW at 12' so thought we had about 5' clearance. Fortunately the mast didn't hit, but the VHF antenna and Windex did. The VHF whip just flexed and survived, but the Windex broke with half landing on the deck and half in the water. Enough of it landed on the deck to identify what is was. Now I know my air draft is 70', but bridges and, even worse, power lines are still scary.
I keep considering adding a cheap video camera to the top of the mast. If you could see the bottom of the bridge you're good, if not, you're going to hit it. May also help see obstacles that are not visible from the cockpit.

 

[smokey73]

I know it's expensive, but I've employed a laser range finder to several bridges..

I've toyed with that idea but I'm not convinced that a laser range finder would be accurate enough to distinguish "inches" of clearance and that is what we are talking about with nearly a 65 foot air draft and nominal bridge clearance on the ICW. I say "nominal" because bridge clearance is from charted MHW (or maybe MHHW, I forget) and with areas with a high variability in the tides, there can be many days with the High Tide above MHW. Shooting at an angle to the bridge you don't get a vertical measurement and by the time I'm under the bridge to get a true clearance (as accurately as the instrument can produce) its too late anyway. I welcome sugestions on who to get the accuracy I need other than feeling my way through with it a little higher each time until my VHF antenna "tings" on the bridge. You can't even have a friend hang over the bridge to take a look as you sail under it because of the bridge construction plus the DOT would probably not like me on a bosun's chair hangin off their bridge.

 

[smokey73]

Anybody know who to contact and how to put pressure on the power's that be to get height boards on a bridge on the ICW!

 

[IH82BL8]

Just a word of advice; know your vessel. I helped a friend move his boat from MD to NC down the ICW. Somewhere along the way we needed a bridge raised. The bridge operator argued with my friend about the total height of the vessel but reluctantly raised the bridge. The operator was mistaken and we would not have cleared. But because my friend was unwilling to trust the operator's judgment, disaster was averted.

 

[Roland5048]

Anybody know who to contact and how to put pressure on the power's that be to get height boards on a bridge on the ICW!

I would start with the DOT. If that doesn't work give the USCG in your area a call. Also, contact your state representative if needed. Good luck.