Recently I was asked "why should I pay for a surveyor, if I or a pinfinder can locate the pins at the corners of my property?" This was my response.
Pins fall over, pins rust out, pins get knocked over by tractors or other equipment and are put back in the ground by the guy running the equipment who's "pretty sure" that the pin was where he put it back.
Yes, they were pinned when it was subdivided. HPP, for example, was subdivided before we became a state. Nanawale was subdivided in 1961. Hawaiian Acres was subdivided sometime between 1958 (when the land was bought by the developer) and about 1962. Sure, there were pins and surveys done -- over 40 years ago.
I just think its smarter to get it redone rather than trusting that the pins that were placed there many years ago are the ones you're finding now. I'd also like to think that survey accuracy has improved since the 1960's.
There's pins clearly visible on an older property that I own. Imagine my surprise when a modern survey was done and it was discovered that part of my wall (that's been there 40 years) is partially on the other property. Thankfully for me, it falls under what is known as "de minimus structure position discrepency" and nothing has to be done.
To quote from a well-respected Hawaiian real estate book, "1997 amendments to our statutes attempted to limit probems arising from encroachments of improvements that were the subject of older, less accurate surveys". (emphasis mine)
On agricultural land (like nearly all of Puna), regardless of lot size, the de minimus structure position discrepency is only 9 inches. So if those 40 year old pins are off by 2 feet on a standard Hawaiian Acres lot and you build against that setback (based on the pins), you could have to move a house.
I've also heard from a knowledgable source that in some area, pins were placed by stretching a mile-long rope between two poles, with paint on the rope marking off each lot boundary. Not exactly scientific and definitely not up to current survey standards.
I've also heard horror stories where the pinning crews accidentally started measuring from the wrong end of a block and each lot may be off by as much as 6 feet. Having a licensed survey will uncover these errors and give you a true and accurate picture of the lot's location and dimension. Plus they are licensed, bonded and insured to give you recourse if an error should occur. A pinfinder has none of those protections for you.
And no, I am not paid by the Surveyor's Licensing Board or whatever they may be called. I've just personally been witness to too many horror stories.