PhotoNewt, thanks for the advice on metering for GND filters. I'll keep that in mind. Any suggestions on which GND filters to get? I've been leaning more toward adding a polarizing filter to my bag before any other filters, but I could somehow be convinced to change my mind.
I think the benches are definitely a bit dark. I should have shot the photo from the other side. If the dock is dark, though, I hope you'll check it on your monitor at home. Perhaps I have mine brighter than it should be. I don't have a calibrated monitor, unfortunately.
Inkista, thanks for showing what can be done with Qtpfsgui. I haven't played with the Mantiuk algorithm much. I've been favoring the Reinhardt algorithms more. What I'm really looking forward to, though, is a "Merge to HDR" feature in The Gimp. I could try to get Cinepaint on my machine, but it's not in the Ubuntu repositories anymore.
Your photos are nice, especially the second one. I'm a bit partial to big rocks in water in the foreground.
If you don't have your own Ultrawide, you need to get one! My Sigma 10-20mm rarely ever makes it off my camera.