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  • Writer's pictureDale Hill

San Diego Coastal SMASH

Total Marks Recovered: 9

Discs Recovered: 7

Non-Disc Type Recovered: 2 (Both new)

GPS on Bench Marks Priorities: 3

New Agencies: 1 (City of Del Mar)

Notes: New Survey Mark Types Found:

  • F - Flange-Encased Rod

  • 63 - Stack

Today's Game Plan

With only two GPS on Bench Marks recoveries so far for the month of July, I decided to make today's main priority catching up on those. I jotted down a list of a half dozen that were located along the coast, then looked for a few other marks that I could pick up along the way.

Being a weekday, I figured it'd be a good day to go back to the Cabrillo National Monument in Point Loma and recover a couple of marks that I missed the last time I was there. My plan was to start from Point Loma and work my way up the coast. This was actually my third trip to Point Loma 🙄maybe there is something to that saying "the third time is the charm"🤣


Missing this mark last month was just a simple oversight, I had a lot of marks on my list and somehow I overlooked this one. This was another new type of marker for me, F - Flange-Encased Rod I'd found a tidal benchmark disc inside one of these hinged sleeves before, but this one was the first where the mark was just a steel rod, this particular one is driven 2 meters into the ground. Another cool thing about this mark is that the stamping "LOMA EAST 1994" is on the outer lip of the sleeve. As you can see from the eye-level photograph, this is just a little off the paved walkway and is very near the Whale Overlook.

AC8021: PLS 7

On my first trip to Point Loma, I recovered a mark designated PLS 3, it was mounted on a curb and was just one of many marks I recovered that day. When I was processing that recovery, I learned there were seven marks in that series PLS 1 to PLS 7, on my next trip I was able to recover all but PLS 7. It's the only one in the series that is not a disc and it's located in a wing wall directly across from the entrance gate to the Park. When I was there last month, it was a busy day, parking was tight, and traffic was backed up to enter the Park, so I passed on trying to recover it then.

Today I closed out the series by recovering PLS 7! I parked at the far north end of the parking lot and walked back to the Park entrance and the Battery Ashburn concrete bunker to look for this brass pin "leaded" into the retaining wall. I had a good idea where it was located based on the directions given in the datasheet, so it was easy to find once I cleared the dirt and debris from the wall.

This series was kind of interesting because there were seven sequentially numbered marks all designated PLS #. Typically PLS is used to note Professional Land Surveyor and is followed by their 4 or 5-digit license number. Most of the marks I've found that have a surveyor's license number are stamped either L.S. or R.C.E (Registered Civil Engineer) followed by the license number.

VM#15697: 941 0179 E TIDAL

I learned about this Tidal Bench Mark on the Waymarking website, it's located in Ocean Beach on the north end of the sea wall. Recovering this one was actually pretty funny, I had coordinates for the mark which I picked up from the Waymarking post, and they got me close, but whether it was my GPS or the person who originally found it, the coordinates brought me to a section of the wall about 10 feet from where I ultimately found the mark.

It was a beautiful day at the beach and there were lots of people hanging out at the beach, I was lucky to find an open free parking spot literally right across from the beach. People were lined up sitting on the sea wall, street performers were doing their thing, vendors had tents set up selling beachwear, souvenirs, and sunglasses. I felt just a LITTLE out of place in my usual hiking garb (5.11 tactical pants, hiking boots, black UA compression tee, my Molle Tactical Utility pouch containing my 'recovery' tools, and my felt trail hat) 😂

I was intently walking up and down the sidewalk switching between scanning the seawall and checking my GPS. A couple of older gentlemen were sitting on the sea wall right where my GPS showed the mark, but when I asked them if they had seen the disc, they had no clue what I was talking about.

I opened the database on my phone and showed them an example of a tidal benchmark and that piqued their curiosity. They both stood up and moved their stuff out of the way to make sure they weren't sitting on it. No luck.

There was a guy sitting at the end of the wall about 10 feet away playing his guitar, when I mentioned to guys I was talking to that the mark might be at the end of the wall, they quickly yelled at Guitar Guy and told him to "get up and get out of the way" so I could look for the disc. 😬 Apparently they were all friends because Guitar Guy got up without fussing at them and low-and-behold, there was the mark!

Inactive Tidal Stations and Vertical Mark Numbers

Up until finding this mark, I thought there were only two Tidal Stations in San Diego, La Jolla (Station ID: 941 0230) and San Diego Bay (Station ID: 941 0170). While researching this mark to enter it into my database, I learned that there are two ACTIVE stations in San Diego, but there are several that are INACTIVE, which means lots more tidal benchmark and tidal station discs to look for! 👊🏻 This station (Ocean Beach) has 5 discs marked A through E. I definitely need to go back and look for the other 4!

Once I learned about the inactive stations, I was able to find the full listing of tidal stations on the NOAA website. I found the Ocean Beach station and called up their Benchmark list which provides full information on all marks cataloged for the station. Here's the listing for the mark I found today:

941 0179 E Tidal Benchmark - Ocean Beach Station

Had I had this information BEFORE I set out to recover this mark, I could have saved a lot of time because the directions to locate the mark are very precise. I've since printed the Benchmark lists for all the Tidal Stations around San Diego and have plenty of Tidal marks to look for!

The other interesting thing I learned was that every Tidal mark has a unique VM# (vertical mark number) while only some have an NGS assigned PID (noted on this sheet as the IDB PID #). None of the Ocean Beach station marks are in the NGS system.

Fiesta Island

This San Diego City Engineer disc is mounted on the curb on Mission Bay Drive just before the entrance to Fiesta Island. This was one I spotted on the Waymarking website and they just listed it as a City of San Diego Benchmark. Since this is a somewhat generic mark I didn't spend a whole lot of time trying to track down a survey that referenced it. I am guessing that 7-91 refers to the date it was set, and NAD 83 refers to the North American Datum of 1983 which is what they likely used when as a reference when setting this.

DC1315: B 1313

This mark was located just up the street from one of my GPS on Bench Marks priorities. I was testing out a new Beta Version of a Passive Mark Lookup Tool put out by the National Geodetic Survey (NGS). It's pretty cool because when you find a mark it lists nearby marks and has them color-coded to show if they've been successfully recovered or reported as not found. This saves a lot of time looking up and opening datasheets, reading through all the recovery notes to see if it's likely to still be there. There were two marks nearby my GPSonBM target DC1435: F 1415, this mark and one that was identified as not found. This mark was located by the off-ramp from La Jolla Village Drive where it intersects with Gilman Drive.

Tic Tac Toe - Three in a Row!

I started out the day with 6 potential GPS on Bench Marks recoveries, three of the marks on my list were all inaccessible because they were located near the train tracks in areas that were fenced off and heavily signed "Private Property". The three marks that I did recover were all pretty easy to find and in good condition. Coincidentally, they are all vertical control marks in the same numbering sequence. I had hoped to make all six recoveries, but these three bring my monthly total up to 5 which means I still have 5 to find in order to reach my self-imposed target of 10 GPSonBM recoveries a month. Two weeks to go, we'll see how that goes! 🤞🏻

DC1435: F 1415 (2 km, Priority B-2 Observation)

Located on Villa La Jolla Drive, just slightly up from the intersection with Gilman Drive.

DC1437: H 1415 (10 km, Priority A-2 Observation)

Located on North Torrey Pines Road, headed northbound as you go down the grade.

DX3651: J 1415 (2 km, Priority A-2 Observation)

Located on the Coast Highway, in Encinitas headed northbound just before you reach the south edge of San Elijo Lagoon.

Another First! Type 63 "Stack"

Yup, I'm still finding "firsts"! It's always nice to end the day on a positive note with an easy recovery; finding the Del Mar Stack checked both of those boxes. 😊 The concrete stack is part of the building that is home to the Powerhouse Community Center, a city-run facility that can be rented out for private events. There's also a nice seaside community park adjacent to the Community Center.

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