Maha'ulepu

East of Poipu resort area is a stretch of a couple miles of coastal area that has been preserved and opened to the public supported by volunteer efforts for the most past it appears.

Overview

Drive toward Poipu Hyatt resort and just keep going past the main entrance onto a dirt road, continue to a T where you go right toward the ocean. This takes you to a parking lot at the west end where you can stop if you've had enough dirt road driving, or go left paralleling the beach to another parking area to the east. Dirt road conditions vary and are hard to gauge but I would say this is "medium" (between really easy to drive and really tough) with just a couple sections that are a bit rough, but most cars should have no trouble if you use common sense.
The eastern parking area is situated on Kawailoa Bay and from here you can go west (to the right facing the ocean) along the beach a good ways, or head out east either along a blocked-off extension of the road or along a path tracing the coast which is more scenic. Either way, the trail extends to the next beach down, Haula Bay. Beyond there some side paths lead into private land where cattle graze and there was a harvested sugar cane field.

Coastal trail to Haula Bay

The trail along the coastline is a little faint - when in doubt don't head inland, there are many false trails - taking you out over the very craggy coastline. The ocean undercuts the rocky coastline here leaving stone platforms extending out over the water and in places there are crevices revealing the pounding water underfoot. The waves and surge create thunderous water spouts hitting the convoluted rock and (unfortunately, I would say) someone has drilled pipes into the rock providing openings for the water to dramatically shoot up, like the Spouting Horn (see below) on the other side of Poipu to the west.
Continuing down the coast early morning was quite peaceful and deserted; other than one fisherman out on the rocks overlooking Haula Bay, I had the place to myself. Perhaps nobody else was out there because a couple of squalls soon swept through bringing perhaps five minutes of moderately heavy rainfall. I ducked into the one place offering shelter -- those rocky overhangs along the coast were right there on the beach, too -- and waiting out the rain while keeping a very close eye on the sea, with solid rock to my back and a small margin before the surf would reach me. Fortunately, the water did not rise (I was under the rock ledge well to the left of the white water splash shown in the photo below and could have easily ran out any time, just a matter of getting wet) and the rains passed.
Once the sun was out I headed back and by then more folks had appeared, including quite a few snorkelers. Walk down the beach back toward the Hyatt was nice with plenty of tide pools along Kawailoa Bay.

Haula Bay

Soap box

• Maha'ulepu is a welcome contrast to the heavy development just down the coast -- Poipu seems to be the south side recreation of Princeville to the north, or if you will a completely built community that looks entirely based on California style culture with only token nods to the fact that it is in Hawaii. I suppose this appeals to (many) people as it's quite popular and pricey, but I move through as quickly as I can, preferring the old town to Koloa inland a mile or so from the beach area lined with million dollar homes and resorts that look like they could be in San Diego to me.
• The cheesy souvenir shops at Spouting Horn tend to keep me away, but it is an impressive ocean "geyser".

Note: Trying to catch up to the present with quick summary for now, leaving out plenty. Will try to update before long. It's very laborious putting together just the text and photos. 
A few photos are here.