For a full description of what I use have a look at my gear page http://www.robgray.com/grayoutdoors/about/about_equipment/digital/index.php
But in a nutshell,
Body for landscapes - 1Ds Mk2
Body for fast movers - 1D Mk2
Lens etc for small things - 100macro, MT24 macro flash, 420EX flash (wireless)
Lens etc for things you can't get close to, things you don't want to get close to - 400 F4 DO, 1.4x, 580EX flash, Better beamer flash extender OR 70-200/2.8 with 2x and same flash.
Nature photography is what got me out in the world,
Yes it's good for that, I sometimes regret getting back into electronics because that is purely an indoor sport. I do occasionally get out, did a 5-day hike through the Karijini NP earlier this year, but that's no substitute for getting out every day.
I used to do a lot of kayaking, inland waters though, you can keep the ocean for reasons you just illustrated.
And since you mentioned eagles and herons I thought I'd use that as an excuse to show two more pics
Wedge-tailed eagle. Around 2-meter wingspan.
A rare morph of the blue heron. This one had the experts stumped for ages.
Closest runin I've had with potentially deadly animal
You can have that, I got caught well away from my car by a lion once, that roar is something you have to experience to believe, thank goodness it's the females that do most of the hunting