BC1414 (Jax) missing. Someone help a newbie verify this, please?

[+The AIIM Team]

I have been over this spot twice on two different days. Unless it is beneath the topsoil, I can't find it. As you can see from the info below it was last surveyed in 1992 (and verified intact.)

 

I know road construction has occured since then in that area. But I am so new at this I don't trust myself completely. I beleive this should be a ground level BM.

 

See my comments on the BM page for more info.

 

http://www.geocaching.com/mark/details.asp?PID=BC1414

 

The triangle I described is clear except for two trees and is about 1 acre large.

 

Thank you!

 

Ivan

 

Complete farking newbie, Jacksonville, Florida

Equipment: Garmin eMap 32MB memory, Rockport hiking boots

[+patw]

I have found that bench marks around the Daytona Beach and Port St Lucie which are listed as being monumented at surface level are often as much as 4 to 6 inches below the surface after just a few years.

Note the line below the lat/long data on Buxley's description page where you made your logged report. This information duplicates that from the NGS data sheet site. Note that the location data is SCALED. That means that the mark is sited with an accuracy of only six seconds. That's plus or minus 600 feet so you're faced with a 1200 foot diameter circle of confusion. The mark may be well below the current surface so I would guess you may need a metal detector to get this one.

Good luck in this and all hour ventures.`

 

patrick & shirley

[+Black Dog Trackers]

Ivan -

 

patw is correct about the SCALED thing. Especially for SCALED BMs, the verbal location is what you must go by, not the coordinates.

 

With these verbal descriptions, I find it helps to sort of read them backwards, starting with the closest item, in this case, the witness post and the two trees (I didn't see any mention of them in your reports). A carsonite witness post, in case you don't know, is usually an inch wide flattish four or five foot tall stake made of a fibery brick-red plastic. It would not be too surprising if it were gone. The trees might be there though, and I'd start with them. (If the trees are gone, you should put that in your report so the next person will know that there will be a big problem with finding this.)

 

The distance from the oak tree is different in 1977 and 1992 (one would think that the 1992 number would be smaller as the tree grew bigger) by one foot, but it is probably the same tree. The cabbage palms are obviously different ones, meaning that the one mentioned in 1977 is probably gone, but if the one used in 1992 is still there, use it.

 

The next closest distance is the centerline of the road, with about a 1/2 foot difference in the two descriptions. All this will give you, of course, is a parallel line. If the road has been widened by a lane or two since 1992, the mark is probably gone.

 

A metal detector will probably be driven crazy by all the pipes and stuff around there. Plus a metal detector is a magnet for various types of authorities, land owners, etc. that might suffer moral indignation if they saw you using one there. If you think you can get close to the station's location, a more discreet tool is a 6 inch piece of coathanger wire, or some such, that can be used as a probe to search for the benchmark in the first 2 or 3 inches of topsoil.

 

If you are just starting with benchmark hunting, I'd advise looking for only the ADJUSTED ones, not the SCALED ones at first. At least with the ADJUSTED ones, a GPS will probably get you within 5 feet of the station. Even with them, the verbal instructions are the most important, with the nearest item being the starting point.

 

The airport ones nearby might be tricky to access. However, less than 3 miles away is BC1588. That one is ADJUSTED and might be an interesting one to find.

[+The AIIM Team]

You are both right. The GPS coordinates are off by about 350 ft it seems from the descriptions.

 

If I follow the described directions, the bm sits near the narrow peak of the triangle, not near the parking lot of the convenience store as the GPS coords would have me beleive.

 

There is one discrepancy in the 1992 directions that I cannot reconcile and that is "bear right on Fort Caroline road." From the direction he is describing, which is Atlantic Blvd to St. John's Bluff Road to Fort Caroline the MCcormick fork is to the right. The road forks, MCcormick Road is to the right, Ft. Caroline is to the left and it has been that way since at least 1992, as that was the first time I was at the intersection personally!

 

BDT, I did not see the witness post and the only trees on the triangle are two small live oaks somewhere near the location described and that is the only vegetation on the entire parcel! Nowhere is there a 3 foot diameter live oak but that doesn't surprise me as local ordnance didn't protect these grand old trees until 2 years ago. A 3 foot diameter live oak is easy to pick out. I had a 5 foot diameter one in my front yard until a year ago when it FELL OVER. (Long story for another time.)

 

You have both given me a lot of new information and I thank you! I will search closer to the narrow part of the triangle next week.

 

There is drainage and residences along those intersecting roads opposite the island. I am still leaning toward the mark being destroyed when the road was widened, but won't it be a thrill if I actually find it!

 

I'm thinking 6 inches of coathanger lashed to a short pole to pick around with.

 

This is a heavily trafficked area. How many times can I poke around here before they think I am a terrorist? LOL!

 

Thank you both again.

 

Complete farking newbie, Jacksonville, Florida

Equipment: Garmin eMap 32MB memory, Rockport hiking boots

[Z15]

When you see a scaled position it means that someone (the team setting the mark originally) plotted it on a USGS quadrangle map and interpolated its position from that. I talked with a NGS leveling recon team in 1996 (part of my job). They were leveling to CORS sites and Harbors of refuge on the Great Lake's. I saw the map they had with all the existing marks plotted as well as the new ones they were setting along thier lines. They did not have any hand help GPS units.