Evidence of that era is in the bay in the form of chunks of machinery, concrete blocks and massive chains.
There is no beach but there is an easy entry in the form of a ladder right into the water from the former pier.
The water gets deeper rapidly. The visibility is usually astonishingly good. Look for it all here, from clouds of surgeonfishes to flashy silverblue jacks and reef-covered boulders. No services, food or water.
Find Mahukona by driving north on Hwy. 270, and turning left between MM #14 and #15. The road is short and parking is usually on the sides. Mahukona fills up with families on the weekends and space can be tight. Bring everything you think you will need. This is country.