Its true that boots may not be great on the slick rocks. But theres also this: Nothing short of large sucker-like attachments is going to be all that great on some of the more slippery obstacles youll encounter on this hike. And really, the Vibram soles of a boot such as the Scarpa Mustang GTX ($165; scarpa.com)a good choice for this hikehave pretty good grip quotients.
So you could do nothing beyond take whatever you plan to use for a hiking boot and probably be fine. Or, you could take along a pair of aqua shoeslight, pull-on shoes specially designed for use around the water. These might come in handy as well if you have to ford any tidepools or streams. Keens Boulder shoes ($90; keenfootwear.com) would be a good choice, as would the Salomon Tech Amphibian shoes ($80; salomonsports.com). The Salomons have a little more coverage, while the Keens will drain more quickly. Both have flexible soles with deep lugs so they will conform to and grip irregular rocks and the like a little better than hiking boots.
I also like NRSs Felt Sole Kickers ($39; nrsweb.com), which are designed for fly-fishers but could be used by anyone around the wet. Felt soles gain their stickiness from the thousands of felt fibers on the bottom. Thats the same principle used by gecko lizards, which can hang from glass. So theyd grip extremely well. Their neoprene uppers also will help keep your feet warmer.
Even more than particular footwear, what will really help with traction and balance is a pair of trekking poles. Most any pair of trekking pole will be fine, so Im not going to recommend Pole X or Y here. But, you do want to retrofit them with a pair of Trek Talonz ($19; dgioutdoors.com). These are steel alloy baskets that have claw-like teeth instead of the less-aggressive basket found on most piles. Theyre particularly good at gripping on steep terrain, and the teeth augment the pole tip for more bite. In most cases you can remove your old baskets, then attach the Talonz with set screws that hold them firmly to the pole. Ive been using a pair this year and like them very much. They snag a bit on brush, but that wont be an issue for you.
Thats a lovely hike. Im sure youll have a fantastic time.