How long for Hydro Survey?

I was hoping someone with more experience would answer. If your unit
doesn't give you any trouble (our SonarMite is really hard to
get going as we have Topcon mixed with something that wants Trimble)
you should be able to do it in a long day. Every 50' would be about 20
ranges each way. The Corps would say you could get 5 or more ranges an hour-
that would be 8 hours for 40 ranges. I would double that and say 2 days.
Also, I would sound with RTK on a pole until it got too deep and then run hydro right
over the same ranges for a check. There are tons of things that can get all
screwed up and you need to have checks however you can. Are you going to
run it as RTK (meaning the different depths get processed as varying rod
heights by the software) or as soundings? With soundings you establish
the surface of the water and then combine the horizontal with a sounding
depth to the water surface. We run ours RTK but it takes some tweaking-
about two typed pages of steps). Take a measurement from the surface of
the water to the bottom of the transducer making sure that however many
people you are going to have in it are there. Don't measure then put in
two more people. I don't know if you need to do a bar check for a pond-
probably but I don't think it will matter that much. A trolling
motor shouldn't affect the depth of the boat from sitting still to moving
the same as moving under power does. Maybe it will- just pay attention to
that also. When the boat moves faster- it rises up somewhat. There are so
many things that can go wrong, it would take me all day to list them out.
I'll quit before I show too much more of my ignorance. (I know just enough
to be dangerous)

Time for me to be contrary

One of the things that I harp about in my Ethics workshops that I teach is people doing work that they are not qualified to do. This is a classic case.

You've never done one before, appear to have no training, don't know what data density to work with, don't know much about the equipment you want to use, etc etc

This is something you should not even be thinking about giving a proposal on unless you intend to bring someone on board that actually knows what they are doing.

And I'd be willing to bet that if you look at your state regs there is something in there about doing work you are not qualified for.

Time for me to be contrary

There has to be a first time for everything. This is no more out of our scope than learning how GPS or Laser Scanning works and adding it to your business.

This is a project with a client that we have a very good relationship with, I have explained to them our current knowledge and limitations for this kind of work. They understand that and are willing to work with us on it. We feel that because of this and because the accuracy requirements are somewhat low (this is for general planning) this will be a good project for us to get our feet wet (figuratively and literally) on. They understand that this project will be our first real world experience with this kind of work but that I also have a basic knowledge of the subject. I have already done significant research on this and if we do win the project with them I will certainly be doing a lot more research and seeking a lot more advice to ensure that we do this properly.

I am primarily seeking some ideas on time and additional advice from more experienced people. We're not doing this in the ocean, moving water, or other more advanced situation. This is a still and clear lake with little to no vegetation.

Hope that clarifies it.

Tom

Time for me to be contrary

Tom,

I would also recommend you work with someone who has this type of experience for the first time around. You will come out ahead on the budget and the learning. Your client will come out ahead also. Your client will also give you more credibility because you showed the professionalism to bring an expert in for your fist job doing this kind of work. Alan talked about all the different things they have to do to get their equipment to work together and that it is still difficult for them. You should be looking for the most up-to-date equipment and software that will bring it all together for you without all the putzing around. The expert will be able to bring you to that point on this one project.

My way of looking at it is this: you can do it the hard, long way by trial and error, or you can learn the easy, fast way with your expert being part of your team from the start. You will be successful in front of your client and you can then start offering more of this type of work to this client and to other clients.

Time for me to be contrary

I'll be counter contrary. I agree about working outside of expertise being unethical. I would think that as long as you research the limitations of your measuring equipment and perform the necessary soundings to verify you are getting expected results, you'd be fine. It's a topo map. I'm sure Fattire has done a topographic map before. Mapping currents might be another thing.

I've seen people have years of experience doing something the wrong way. Aptitude makes a difference.

Time for me to be contrary

Set some stakes on the shore to keep you on line, put a couple of sections of range poles together and sound from the edge of the water till it gets too deep and then hydro down the same lines. If they match, wah-la, you is a hydrographic surveyor 😛
If they don't, go back to square one and retrace your steps till you figure it out.
If you can't figure it out, fasten a weight to a cloth tape and sound it all like the good old days. If we can do it, I know you can- it ain't no biggie. Good luck.

We do a hydro survey on a 24 ac. lake once a month and we rent the equiment from these guys, http://www.ses-services.com/

It take us about 1/2 day using an airboat, the lake does not have a boat ramp so we dump an airboat from the trailer onto land and run it a few yards to the water. We average about 100,000 points per the 1/2 day at approx 5 knots. Once back at the office it takes about an hour to reduce the file to about 3000-4000 points because many of the points are too close to each other.

You can see the points on a laptop in real time while collecting the data so if you miss something you can go back and catch it.

We then begin drafting a contour map using the 3k-4k points which takes another 1/2 day to a day depending on the deliverable for that month.

Sometimes in the real shallow water, 3' or less we might use a level rod and GPS.

Used a Jon boat with a trolling motor with a SonarMite connected to a TSC2 with Survey Controller a couple of months ago . Loaded a grid in the controller as a guide, set it on continuous topo at 25' intervals, covered about 18 acres in about 3 hours actual boat time. Not much to setting it up, came with a 2 meter rod if I remember right. Just set it to record actual elevations, not depths, take a few shotts and check with a level rod.

Randy,

Any chance you can shoot me an email with the details of how you set that up? Did you buy or rent the equipment? THAnks.

Andy

The company bought it. Have to do it again in a week or so to check how much rock they've dumped in Kentucky Lake. Wasn't much to it, Survey Controller has the option for the SonarMite already installed in it. Bluetooth connection to R8 and SonarMite. Comes in a nice big Pelican case with a rod and bracket to attach it to the boat.

Is there anywhere or any way to get that boat clamp/attachment by itself? Or anything similar? Specifically need an attachment that allows for the transducer/gps to be adjusted to plumb when the vessel causes it to be somewhat off.

Don't know if you can order the bracket separately. Here's a pic showing what it looks like. Can be adjusted to vertical.

http://www.allenprecision.com/used-equipment/hydrolite-tm-singlebeam-echosounder/

If you need more detailed picture I can take one Monday.

Hiring a Consultant and/or a Certified Hydro Trainer may be the way to go for your first Hydro project, learn the HW and SW and Best Practices. Get the job done right the first time, on-time and under budget, limit your legal liabilities, if Hydro projects are a good fit for your business, invest in the HW and SW.

-BbB B-)

I have a new unit for sale that has never been in the water. Mounting brackets, survey pole, carrying case, bluetoth model.

Do you still have the Hydrolite equipment for sale? If so, please email me: jason.miles@bearingpt.com