Why not try something new today?
During the blue hour it's almost bright enough to see the horizon, yet it's still too dark to take sharp pictures. Metering off the water, I will need a 16-second exposure... but steady lapping waves will keep this boat in constant motion... and that's a problem... or is it? Wait... Why not build that swaying motion right into my composition? A tack sharp horizon with the foreground blurred in blue? Will it work? Fiddle... fiddle.. done. Enjoy.
(Pixel-peepers: During the blue hour, a steady tripod is a must. Meter for your mid-tones even if it means part of your composition may be too dark. That's how a scene looks like during the blue hour, and that's how you want your final photograph to turn out.)