Author Topic: Searching for a Large RC Warship Lost in Golden Gate Park (Read 16775 times)

Rob Wood · « **on:** August 22, 2012, 02:25:12 PM »

New to the forum, looking for help in finding my sunken battleship.

This is a bizarre story, and I need help figuring out how to find my radio controlled battleship. It's approximately 4.5 feet long, fully-equipped for combat: fiberglass hull, 2 rotating turrets armed with stainless steel triple 7/32" (about 5.5 mm) barrels, 2 triple torpedo launchers of the same caliber, a CO2 bottle, a regulator, firing valves, waterproof servos, radio receiver and automatic bilge pump. It was lost in a collision with another boat two weeks ago today during a night event held at Spreckels Lake, a model-boating lake in Golden Gate Park.

The lake is approximately 150 yards across, but as it turns out, is only 3'-4' deep. Even standing in the muck in chest waders, the water comes to mid-chest at the deepest. But visibility is, for all intents and purposes, zero. On the other hand, the bottom is virtually flat and weedless. I bought a Humminbird 120 Fishin Buddy last week, hoping to use it to find my ship, but it's not doing the job. According to Greg Walters at Johnson Outdoors, I need something a lot more sophisticated - and a lot more expensive - to find my ship - something in the Side Imaging category, a 798 model or better. I don't have the cash for one of these units, but would be willing to pay someone who has one to help me.

Anybody close to San Francisco willing and able to mount an expedition to Spreckels Lake in Golden Gate Park?

Here's what the ship looked like when it sank:

Thanks!

Rob Wood

ITGEEK · « **Reply #1 on:** August 22, 2012, 02:35:34 PM »

Rob,
That sounds like a bad-ass toy.
If it were me, I'd get a powerful magnet and drag the lake
with it.

Rob Wood · « **Reply #2 on:** August 22, 2012, 02:52:03 PM »

It's definitely a bad-ass toy! We have battles, Axis vs Allies, and deliberately try to sink each other. But that's in our regular pond, in 7 feet of clear water. This is basically brown, with zero visibility.

The problem with your suggestion of a magnet is that all of the metal above the deck is stainless steel.

Rob

Jim Jack · « **Reply #3 on:** August 22, 2012, 03:10:02 PM »

First, let me say sorry they sank your battleship. Second, I'm not in your area.

Do they let bass boats on that lake? SI works best with a steady forward speed of 2-4 mph so a boat would have to be able to launch and recover on that lake to even mount an attempt at finding it with SI.

Do you have an approximate location? If so waders, one of those grippers things used to get stuff off of high shelves (Home depot/Lowes both sell them, and some time/effort may be viable option.

You could try posting here http://www.bbcboards.net/humminbird-sonar-gps/. I know there are some guys from you area that post there.

Roddy · « **Reply #4 on:** August 22, 2012, 03:12:06 PM »

Rob, Welcome.

1. Drain the lake !

2. Sense ships are hardly ever found were last seen at sinking, Drain the lake !

3. Rent a ROV and spend BIG BUCK, Drain the lake

4. Send me a PM ASAP !

Roddy

Rob Wood · « **Reply #5 on:** August 22, 2012, 03:57:10 PM »

I have permission to use a boat, but not wade. (Obviously, if we discover my ship, I'm getting into the water if I have to to retrieve it.)

Just FYI, I waded in a grid pattern (as accurately as possible), probing with an 8' pole, for 2 1/2 hours, until a park ranger kicked me out of the lake. Then I did it again with a buddy, side-by-side, for another 2 1/2 hours a few days later, until a police officer confronted me. I'm trying to get official permission from the park supervisor to do a thorough search on foot, and if I get it, I'll get 4 other guys to wade with me, if all else fails.

On a bass boat in the lake: Yes, we could launch a bass boat with the blessings of the powers-that-be, but there's no ramp. We would have to pick it up and place it in the lake. We have a dinghy we've been using, but it's too small.

On the link you supplied: Thanks! I'll check that out.

Rob

Quote from: Jim Jack on August 22, 2012, 03:10:02 PM

First, let me say sorry they sank your battleship. Second, I'm not in your area.

Do they let bass boats on that lake? SI works best with a steady forward speed of 2-4 mph so a boat would have to be able to launch and recover on that lake to even mount an attempt at finding it with SI.

Do you have an approximate location? If so waders, one of those grippers things used to get stuff off of high shelves (Home depot/Lowes both sell them, and some time/effort may be viable option.

You could try posting here http://www.bbcboards.net/humminbird-sonar-gps/. I know there are some guys from you area that post there.

Humminbird_Greg · « **Reply #6 on:** August 22, 2012, 04:00:38 PM »

Guys, basically he is looking for something projecting up off of the bottom. An Si transducer on a pole can be rotated slowly and would show this clearly enough (Rickard has shown us that this works!). Make an Si unit portable with a smaller battery and mount the transducer on a pole. It should not take that long to find the ship.

Jim Jack · « **Reply #7 on:** August 22, 2012, 04:24:21 PM »

Greg, we need to find someone with a 798 with internal gps in his area to do that.

For most us it would mean either unrigging our units from our boats or purchasing power, td, and gps.

I'd love to help the guy out but I'm further East than you.

sonar2000 · « **Reply #8 on:** August 22, 2012, 05:31:09 PM »

I would check with dive teams and see who would like to perform a training session in the lake. They can get permission a lot easier than a citizen.

Probably find it quicker than sonar in this case.
A lot depends on the bottom makeup of the lake..

Chuck

Rob Wood · « **Reply #9 on:** August 22, 2012, 05:42:28 PM »

That sounds like a possibility. I'm waiting for a call back from the Golden Gate Park superintendent as to the possibility of getting permission on any terms at all to bodily enter the lake to search for it.

Rob

Quote from: sonar2000 on August 22, 2012, 05:31:09 PM

I would check with dive teams and see who would like to perform a training session in the lake. They can get permission a lot easier than a citizen.

Probably find it quicker than sonar in this case.
A lot depends on the bottom makeup of the lake..

Chuck

Rob Wood · « **Reply #10 on:** August 22, 2012, 07:00:09 PM »

Good news! Park Superintendent has given us permission to wade in the lake! That opens up some avenues, and relieves some of the stress.

Rob

rnvinc · « **Reply #11 on:** August 23, 2012, 01:23:22 AM »

This might help cut the search time down...

(If the vid doesn't show up in your browser.. Click the blue link right above my signature at the bottom left of this post)...


Using the seine net

Rickie

ITGEEK · « **Reply #12 on:** August 23, 2012, 08:29:40 AM »

Yea,
Get yourself two canoes, and a person to paddle each one.
Get a long net like the picture and attach each end to a canoe.
It should make quick work of the search.

Rob Wood · « **Reply #13 on:** August 23, 2012, 10:24:01 AM »

The net in the video obviously has a lot of drag and weight, and I doubt that two canoes would work. But now that we have permission to wade in the lake, it would make sense (to me, anyway) for two guys to walk forward with a weighted net between them, with a 3rd guy in front to check out anything the net snagged.

Rob

ITGEEK · « **Reply #14 on:** August 23, 2012, 10:34:58 AM »

Rob,
Once you find your neat toy, for future night battles.
Install a flashlight in it that is shining straight up.
Then, if it sinks, it will be easy to see it and throw a
marker buoy on top of it.

Rob Wood · « **Reply #15 on:** August 23, 2012, 12:22:48 PM »

Excellent suggestion! In this case, the ship was strung with very bright LEDs, and I did see them shining under water - briefly - as it went down. The main problem is that there is literally not more than 8 - 10 inches of visibility in this lake. It also had its own marker buoy installed that automatically deployed when the tugboat collided with it and rolled it upside down. When it rolled back upright, the marker buoy wrapped around the hull and string of lights. By the way, this was not a night battle - it was supposed to be a sedate parade of lighted boats.

Rob

rnvinc · « **Reply #16 on:** August 23, 2012, 01:33:40 PM »

Do you presently have video of this beast in action....?? (before it sank I mean)...(sorry)..

That would be Oh-so-cool to see...!!

Rickie

Rob Wood · « **Reply #17 on:** August 24, 2012, 11:27:11 AM »

I think I do have video somewhere. Will have to check.

Rob

Rob Wood · « **Reply #18 on:** August 25, 2012, 03:10:18 PM »

Spent the day at the lake yesterday, searching by wading, dragging a net behind the boat, and trying to get the 120 Humminbird to locate the ship, with no luck. Anybody have a high end side imaging unit in the San Francisco Bay Area who would be willing to help me? I'm willing to pay for the help.

Thanks,

Rob

sonar2000 · « **Reply #19 on:** August 25, 2012, 04:06:18 PM »

Dont know that even the high end sonar will help. You are in very shallow water.

I still think divers in a grid pattern is the best. The park should let you use them for training and it will be very good for them to practice..

Rickard · « **Reply #20 on:** August 25, 2012, 04:31:56 PM »

I think a sideimaging sonar can help. I have scanned quite alot in just 2 - 3 feet with water and got useful results up to 40 - 60 feet to either side. A dingy (or a Porta-Bote, I love mine) with a Minnkota will be a perfect platform. Some kayaking folks could help too.
Rickard

Rob Wood · « **Reply #21 on:** August 25, 2012, 10:54:16 PM »

On divers: Visibility is virtually zero (less than 12 inches). I've had two divers who are also model boat enthusiasts look at the situation, and shake their heads. I haven't ruled it out, though, and now that the park supervisor is supportive, that's definitely an option.

Greg Walters, Humminbird senior tech support, and Bob Herzog, manager of the South San Francisco West Marine, both feel pretty strongly that the higher end side imaging units can do the job. I think it would be a golden opportunity to prove the versatility of one of these units, and since I'm a journalist, photographer, videographer and web developer, I'm willing to put together a YouTube video and magazine article about the challenge - successfully met, of course - and all of the players in it. They can all use this material on their websites and in their marketing materials.

What I want is a high-end unit that can not only spot a large fish, but clearly show what kind of fish, whether it's swimming or on the bottom. I want that, and a skilled operator, at Spreckels Lake on a Friday or Sunday. I'm pretty sure that somebody is going to step forward and meet the challenge.

Rob

Drifter · « **Reply #22 on:** August 26, 2012, 10:04:12 AM »

Rob,

I don't think you'd need a high end unit to find your ship PDQ.

Something like this ought to do ...

< click to enlarge >

=>

It does sound like a tailor made training OP / PR expo for your local LEOs to do a little SAR. I'd take you up on the challenge if you were a little closer ( Gainesville, Fl to: San Francisco, CA 94121 ~~~ Spreckels Lake ).

Let us know what you turn up,
Darrell

Rob Wood · « **Reply #23 on:** August 26, 2012, 11:21:18 AM »

Darrell,

I am a complete newbie at all of this, so please excuse the dumb questions:

1) What, exactly, am I looking at in the photos?
2) What is meant by LEO?
3) What is SAR? (Search and Rescue?)
4) Would the unit in the photo work in 3' of water?

Thanks,

Rob

Drifter · « **Reply #24 on:** August 26, 2012, 02:51:13 PM »

Rob,

1) What, exactly, am I looking at in the photos?

The first and third shots show a Humminbird 798ci "bottom of the line" SI unit that is setup in a portable configuration. It runs off of a small 12V sealed battery. Both are carried in a small soft sided cooler. The second shot shows the transducer mounted on a "towfish" - which hangs over the side of the canoe. The last four shots are screen prints taken from a laptop that is using one of several freeware programs to review sonar recordings made using the Humminbird SI units. The sonar recordings are saved on standard SD cards. The first screen print shows a lake bottom which is around eight feet deep straight down and gets shallower on the left side all the way up to the shoreline. I would guess that your ship would show up similar to one of the small logs to the left side of the image.

2) What is meant by LEO?

Law Enforcement Officer

3) What is SAR? (Search and Rescue?)

Correct.

4) Would the unit in the photo work in 3' of water?

The towfish only needs to be deep enough to "see" under the bottom of the canoe.

=====================================================

If you had the right platform, it should be possible to mount a 798ci unit, a small battery and the transducer to one of your community's RC craft. A decent sized catamaran might work. You would need a laptop with the HumViewer program to review the sonar recordings on site. Power up the SI unit, tell it how wide an area to scan, set it to record and then put it in the SI view mode. Run one tract lane across the lake and one back about forty feet off from the first. Stop the recording, remove the SD card, plug it into the laptop and review it using the HumViewer program. That is just a rough outline. Here is a screen print from HumViewer showing the GPS tracklog (sometimes called a bread crumb trail) to the lower left. The blue dot is the vessels position corresponding to the SI image shown on the right.

If all you were looking at was an up and back U-shaped path, it would be fairly easy to estimate the "target's" position. If you had internet access you could overlay the tracklog in Google Earth to get an overhead orientation. Here is an example ( from a different tracklog ) of what is displayed in Google Earth ...

Links:

HumViewer program

Humminbird 798ci HD SI Combo GPS Fishfinder

Sealed 12 Volt 8 Amp-hour Battery

There was an old post I looked for and couldn't find that had a remote operated platform - so it has been done before. If you picked up a used 798ci SI unit and upgraded to the HDSI transducer, you could probably put the pieces together for somewhere reasonably less of the price of a new 798ci SI unit. I paid $150 for a new HDSI transducer in 2011, but it looks like the price went up since then. You might get a used one from someone around here that's looking to move up to the LSS-2 transducer .

Hope some of that filled in a few of the gaps,
Darrell

newkid4si · « **Reply #25 on:** August 26, 2012, 10:17:58 PM »

Rob Wood
Here's my suggestion. Contact a local BASS club and tell them your situation.
Many of the members have state of the art electronics. Also as many of the local
waters are electric motor only, small boats should be available.
I'd put a bounty on the boat and step back.

Mike

If Hi's tackle shop is in your area, he could put you in touch with someone.

Rob Wood · « **Reply #26 on:** August 27, 2012, 12:31:39 PM »

Darrel,

Thanks for the detailed answers! We could, in fact, mount such a unit to one of our large models. We have a 1:144 ocean liner that's close to 8' long.

Mike,

Thanks for the suggestion to contact a bass club! HI's tackle shop is only 15 minutes from me, and I'll stop by there today.

You guys are great!

Rob

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