While reviewing a rural survey recently, my "oh, my" alarm went off in my head. The current survey made reference to two prior surveys within the same aliquot part of a PLSS section. Surveyor A had made a survey in the 1990s. Surveyor B had worked nearby in 2010 and found the monuments set by Surveyor A. The current survey firm found all monuments set by both A and B. They concurred with Surveyor B's work. On the plat, they listed the GLO distances, the distances of A and the distances of B plus their own numbers. Somehow, the distances between identical pairs of bars were 50 feet to 70 feet different. How on Earth did Surveyor A have distances so much shorter than the other two surveyors? Same monuments. Vastly different distances. All available at the county courthouse. I have followed the work of all three surveyors and have always found them to be qualifed and professional.
Pure guess - hand annotation and no proofreading by a professional.
In my current position I see a fair amount of work done by others. It is my opinion that in a lot of cases the work is done by very green and minimally supervised technicians and not checked by the PLS before signing.
I'm working on one now where my parcel was surveyed in 1978 and the adjoiner had a survey done last year.
In 1978, the surveyor set rods along the common bounds extending out about 1,700' into a swamp and at the rear corner.
Last year's surveyor never found them or showed them on his map. Not sure how he tied into the original survey but claims to as he states the original survey as his bearing base. He went out with his client and placed flagging "close to the line" as "he had problems with his gps" or so his client told me.
Well in under two hours I found all the irons including the rear corner and the next corner north. None had any flagging and probably hadn't been seen in 40 years. The new surveyor had a line flagged about 50 away.
I see a lot of this and pincushioning due to crews not going back to look for points before staking "computed" points or sweeping with a metal detector before setting a corner.