Looks very pretty.
I hear you on trip-specific gear: my bike tools come in at something like 5#, even if they don't take up much volume. Finding ways to do more with less is always nice, especially after a long day of moving.
Not sure I'd want to get down into that water in freezing weather. More trouble than it's worth, it seems. But, if that's what makes you happy, go for it!
Thanks for sharing.