I parked one night at the end of March in the rental slips. They are located next to the park service slips and are best accessed from the open water entrance on the south side of the marina complex. The water depth and distance to shoreline were getting marginal then to navigate around the last monthly rental slip...I wouldn’t have wanted to drive in there without good water visibility and wondered at the time if the houseboats on the west side of that slip were stranded until the slips were either moved or the water started rising. With the water on the rise, I’m guessing it’s better, but there is a shallow ledge on your port as you go in.
As far as a hike, as PowellBride posted, the rental slips are close to shore adjacent to the lighted night fishing site on the dock. If you’re asking about access to the marina parking lot, it is up the hill on a new wide concrete path. Not bad for just walking. It would be a hike carrying a lot of gear. In the summer months there are kids driving golf carts up and down carrying people and gear. They weren’t operating a month ago and the snack bar and store on the dock were still closed (as well as the snack bar at AP.). They may be open by now. The dock itself is considerably wider now to allow passage for the carts. We walked to the hotel at the top of the main ramp to eat that night and it wasn’t a bad walk...it helped that it was a nice cool March night, and we were hungry...YMMV if it’s hot. I would add, I hadn’t eaten in that dining room for years and have to say their fancy named version of a French dip was one of the best I’ve ever eaten. Well worth the walk, and probably partly due to off season, they seated two guys in jeans and ball caps in the main dining area when we had planned on just eating at the bar.