"Howard" wrote

It is hard to compare locations from your photo but............from what I
can see, the photo you attached is mild compared to reversing falls.


You are quite right. The photo, like most photos of rough water, doesn't
begin to do it justice. The picture was actually taken looking towards the
difficult part.

Take a look at this chart section:

http://home.maine.rr.com/rlma/HellGate.jpg

You would have a hard time turning a 30 foot boat around at slack water in
the narrow part to the left of the 10. Note the rocks indicated on the
bottom over which the current runs at 4 - 5 knots. This is only the Upper
Hell Gate. The lower one often has a visible drop of a several feet similar
to the reversing falls but only in one direction.

The bridge clearances and water depths for the St. John are suitable for
larger vessels than could ever get through the Hell Gates so I can't imagine
the reversing falls are too tight.

Not many sailboats go through the Hell Gates. I did extensive planning to
be sure of doing it at high slack water. I still don't know how I managed
to hit it at maximum flow but I suspect the tide tables on the web site I
looked at use an algorithim that doesn't take the complex local differences
in channel water level into account. I've since discovered that there are
some dedicated current prediction sites for this spot.

If you are ever in this part of Maine though, it is a passage not to be
missed.

--
Roger Long