No - not all have the boards, not by a long shot. And I make no assumptions.

But, as it turns out, this is not a big issue for me. I have a 47 foot mast (above
water), plus antenna, so I figure I need 50 feet. Most bridges are either 65 feet fixed -
that's the standard for high bridges on the ICW - or lower draw bridges. There are
relatively few that are close enough to 50 feet to be a bother. When we do encounter to
tight fit, I take the time to study the tables carefully. The most frustrating bridge is
on the Danvers River, where I hauled out several years ago. There is a new bridge that is
listed as 47, 48, or 49 feet in various charts and guides. When we went in, the board was
hanging sideways!



"Donal" wrote in message
...

"Jeff Morris" jeffmo@NoSpam-sv-lokiDOTcom wrote in message
...
Well put, Scotty.

But MC does have a point - under the US system you have to check to see if
the current
tide is much higher than MHW; in other countries where the datum for
bridge clearance is
the Spring Tide level, or the Large Tides, its a bit easier.

However the best thing to do is to read the gauge board on the bridge and
ask the
tender.Can

Hmmmm.... You assume that every overhead obstruction has a guage!

I suspect that "busier" waterways have guages, but most of the rivers that I
have gone up, have not had such useful aids to navigation. I need to read
the charts!

Regards


Donal


--

Yes, that's it, that's what I was saying. Thank you Shen.

Scotty


"Shen44" wrote


I think he's saying that US charts require the operator of the vessel to
pay
attention to his/her surroundings, know how to read the charts, know how
to
make use of the information provided, and know how to apply that
information to
other variables which may make the "datum" inaccurate, for a given moment
.....
now that I think about it, so do B.A. charts.
No chart/system, is perfect. You need to know which system you are using
and
what it's plusses and drawbacks are.

Shen

Overhead wire????? he he he


"The_navigator©" wrote in message
...
How do you have a tide guage on an overhead wire?

Cheers MC

Jeff Morris wrote:

Well put, Scotty.

But MC does have a point - under the US system you have to check to see
if the current
tide is much higher than MHW; in other countries where the datum for
bridge clearance is
the Spring Tide level, or the Large Tides, its a bit easier.

However the best thing to do is to read the gauge board on the bridge
and ask the
tender.Can


"Scott Vernon" wrote in message
...

Well, DUH!

"The_navigator©" wrote ...

Hmmm. That's a worry. Might mean you'll need tide tables to decide if
you can pass an overhead...