jimbaerselman
Well-Known Member
I suppose the green lumpy bits dont move very often.
Except in a few earth-movement prone areas - and then they're often discovered by bumping them!
Estuaries are another trap. Shifting sandbars after the winter floods or the big gale. Sadly, again, it might be you discovering the change.
But the biggest source of uncertainty is the change in port/marina layouts and new breakwaters.
With fully corrected charts in 2007 (give or take a year) I arrived at Bilbao from the east in a strong northerly expecting an easy entry to a port of refuge at night. I could make no sense of numerous yellow lit buoys, but GPS did give me a clue as to where the starboard entrance green may be. But what about all those yellows en route? Gulp . . . Kept outside all the yellows until very near the green, then turned south when we could see the end of the westward breakwater.
It turned out yellows marked a (then new) sunken breakwater - leading to a new red light - which hadn't yet been lit - as we later discovered. The trouble is, it wasn't so easy to pick up NOTAMs before reliable internet.
Nowadays, the CA's Captains Mate seems to fill that gap. Thousands of reports a year note the nasties as they're discovered. And the nice bits, too.