Hey Dave,

...he went up the Back River, instead of the Mackay River behind Lanier Island (indicated by the yellow pointer at the top of the pic) ... The two rivers actually have a similar curvature, and each have bridges roughly the same distance up from the Sound... However, the one on the Back River is only a 40' vertical clearance...

For those not familiar with the area, from off the northern tip of Jekyll Island, the ICW proceeds up the Mackay River, just to the left of the yellow pointer at the top of the photo below...

The Back River is the next one over to the left, in between the Mackay and Brunswick... The same causeway out to St Simons crosses that one as well, only with the lower bridge... There very well may not have been clearance boards on that one, but how anyone mistakes a 40' bridge for a 65' is still mystifying...

Hell, aren't chartplotters, iPads, and programmed routes supposed to prevent this sort of stuff from happening? (grin)