Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 28-01-2019, 08:00   #1
Registered User
 
geoffschultz's Avatar

Join Date: Sep 2003
Location: Marlborough, MA
Boat: Freedom 40/40
Posts: 62
Bottom contour mapping via a dinghy

I've been taking my 5'5" draft Freedom 40/40 in & out of the Rio Dulce in Guatemala since 2001 and have never had a problem. There's a bar at the entrance that's probably 1/4 mile wide and we always cross at the astronomical highest tides of the month. Last year we bumped very hard multiple times when going out and we had to get pulled across using 2 dinghies with 15 HP motors to make it in. We have a 6' wide wing keel, so heeling the boat doesn't help.


I've been using the same/current waypoints for years, so I suspect that the channel has moved or silted in. My goal is to take a dinghy out with some kind of sounding device to map the bottom contour before trying to take BlueJacket out through it.



Does anyone have suggestions for a reasonably priced solution to this? In the past I've just taken a hand held depth sounder and a handheld GPS and mapped things that way, but I was looking for something more automated.
__________________

geoffschultz is offline   Reply With Quote
Old 28-01-2019, 08:04   #2
Registered User

Join Date: Oct 2010
Location: Abaco, Bahamas/ Western NC
Boat: Nothing large at the moment
Posts: 962
Re: Bottom contour mapping via a dinghy

Put an inexpensive Hummingbird, transom mounted transducer on your dink. I always had one on mine as I have a habit of going where no man has gone before. Really helpful in cloudy water.
__________________

Tingum is offline   Reply With Quote
Old 28-01-2019, 08:13   #3
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Cowes (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 25,669
Re: Bottom contour mapping via a dinghy

Quote:
Originally Posted by Tingum View Post
Put an inexpensive Hummingbird, transom mounted transducer on your dink. I always had one on mine as I have a habit of going where no man has gone before. Really helpful in cloudy water.

I am also interested in this. Will such a Humminbird record the depths with the GPS coordinates, so that we can display them on a computer or a plotter?


Have you done this?
__________________
"Parce que je suis heureux en mer, et peut-ętre pour sauver mon ame. . . "
Dockhead is offline   Reply With Quote
Old 28-01-2019, 08:33   #4
Registered User

Join Date: Dec 2007
Posts: 165
Re: Bottom contour mapping via a dinghy

The bigger question is what do you do once you gather the data. I am so frustrated with Navionics/Garmin/Active Captain which has collected community depth data and then is now making them harder to use for those that don't pay for their charts.

Please consider a mechanism of collecting this chart/depth data and uploading to openseamap. Perhaps we can break the yoke the commercial co's have on OUR community reported data. https://depth.openseamap.org/
night0wl is offline   Reply With Quote
Old 28-01-2019, 08:48   #5
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 36,376
Images: 241
Re: Bottom contour mapping via a dinghy

Every year, over 16 million recreational boats traverse the nation’s coastal waters, compared to NOAA’s fleet of five hydrographic vessels. A high percentage of these boaters, especially among the larger vessels,use GPS and echo sounder systems, and in essence collect new, high quality depth data every time they transit from one place to another. TerraNautical has assembled and tested a device that captures and records
these data and has developed and tested a way to process the data to NOAA specifications utilizing a NOAA-style Quality Assurance review.
https://www.terranautical.com/paper/tndhydro.pdf

Recreational boaters are already “collecting” data. However, just as quickly as their sounding data flashes onto their depth sounder it is, regrettably, lost forever. However, this does not need to be the case. With the advent of small high capacity microelectronic storage devices (CompactFlash), mobile telecommunications, and precise positioning technology such as WAAS GPS, most of these vessels could be recording the sounding data needed to improve nautical charts.
https://www.terranautical.com/paper/...tm#_Toc2911181

Unfortunately, I don’t see any information on the actual “devices” they propose using.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 28-01-2019, 08:49   #6
Registered User
 
Jammer's Avatar

Join Date: Jan 2010
Posts: 1,306
Re: Bottom contour mapping via a dinghy

I use a Vexilar SP300 module connected via WiFi to an Android smartphone running Navionics. The SP300 is inexpensive ($150) and self contained, powered by its own gel-cell battery. Attaches to the survey boat with suction cups. Battery life between charges is longer than I've ever tried to run it, at least 20 hours.


There are other depth finders available that will provide the necessary data feed, but the Vexilar is the least expensive and most portable that I have found.



Any smartphone or tablet will work. I use a Galaxy S8, which is water resistant (IP67), and provides about 4 hours of useful battery life for surveying.



Navionics will collect the data and construct a contour map as you move around. You would then use the same smartphone while navigating the channel with the mother ship, as there is no straightforward way to transfer the data to a chartplotter.


The Navionics software is free to install but there is an annual chart subscription fee charged on a regional basis. It is not expensive.



The navionics application will also upload the data to Navionics' servers once an internet connection is available, and Navionics will then review the data and incorporate it into future chart updates, usually after a few weeks.


I do believe that openseamap is worthy of our support but am not sure that it solves this particular problem.
Jammer is offline   Reply With Quote
Old 28-01-2019, 09:01   #7
Registered User
 
Jammer's Avatar

Join Date: Jan 2010
Posts: 1,306
Re: Bottom contour mapping via a dinghy

Here is an example showing the confluence of the Mississippi with a local stream that forms a little inlet. The just-collected data is shown in red. It is possible to adjust the transparency and color to make an effective chart for your situation. In this example, you can see that the inlet has considerable shoaling.
Attached Thumbnails
Click image for larger version

Name:	Screenshot_20190128-095657_Boating HD.jpg
Views:	120
Size:	408.8 KB
ID:	184626  
Jammer is offline   Reply With Quote
Old 28-01-2019, 09:09   #8
Registered User
 
Jammer's Avatar

Join Date: Jan 2010
Posts: 1,306
Re: Bottom contour mapping via a dinghy

I had zigzagged around the inlet to try to get as much data as possible. A limitation of this approach is that the software-generated contours can make it look like there's data for areas that are not well sounded.


This survey was via canoe from an access upstream as planning for using the inlet to anchor in the future. It's a pretty little area.


There are some implausibly deep areas that are due to limitations of the sounder. If the depth is less than about 12", it will report over 30'.
Attached Thumbnails
Click image for larger version

Name:	Screenshot_20190128-100418_Boating HD.jpg
Views:	72
Size:	398.4 KB
ID:	184627  
Jammer is offline   Reply With Quote
Old 28-01-2019, 10:03   #9
Registered User

Join Date: Dec 2010
Location: W Carib
Boat: Wildcat 35, Hobie 33
Posts: 11,327
Re: Bottom contour mapping via a dinghy

Quote:
Originally Posted by Jammer View Post
I use a Vexilar SP300 module connected via WiFi to an Android smartphone running Navionics. The SP300 is inexpensive ($150) and self contained, powered by its own gel-cell battery. Attaches to the survey boat with suction cups. Battery life between charges is longer than I've ever tried to run it, at least 20 hours.


There are other depth finders available that will provide the necessary data feed, but the Vexilar is the least expensive and most portable that I have found.



Any smartphone or tablet will work. I use a Galaxy S8, which is water resistant (IP67), and provides about 4 hours of useful battery life for surveying.



Navionics will collect the data and construct a contour map as you move around. You would then use the same smartphone while navigating the channel with the mother ship, as there is no straightforward way to transfer the data to a chartplotter.


The Navionics software is free to install but there is an annual chart subscription fee charged on a regional basis. It is not expensive.



The navionics application will also upload the data to Navionics' servers once an internet connection is available, and Navionics will then review the data and incorporate it into future chart updates, usually after a few weeks.


I do believe that openseamap is worthy of our support but am not sure that it solves this particular problem.
Ive got a similar Vexilar unit permanenlty installed, but its also intended to be portable so you could put in dink to do exploration.

Integration with Navionics is easy and it saves the data of the track including GPS locations and displays on charts.

To my knowledge Vexilar's phone app is only a fish finder like display which does not store any history.
belizesailor is offline   Reply With Quote
Old 28-01-2019, 10:08   #10
Registered User
 
mvmojo's Avatar

Join Date: Mar 2018
Location: www.mvmojo.com
Boat: Robt Beebe Passagemaker 49-10 in steel
Posts: 217
Re: Bottom contour mapping via a dinghy

Years ago I and some others had an idea to out fit a remote controlled battery operated boat with a depth sounder. If unsure about a channel, send it out ahead of the big boat. At that time, the bugaboo was getting data back to the big boat. Now, with Wi-Fi, it should be fairly simple. Never did anything with it, but I'm sure there's some smart folks on this forum who could make it happen.
mvmojo is offline   Reply With Quote
Old 28-01-2019, 10:16   #11
Registered User

Join Date: Jun 2017
Location: Waterford, MI
Boat: S2 11.0a
Posts: 64
Send a message via Skype™ to RobinScurr
Re: Bottom contour mapping via a dinghy

I have a Vexilar SP200 SonarPhone T-Box on my dinghy, but I have an electric start motor, so have a battery. It's meant to be a fish finder, but also can be used to map bottom contours. You use Navionics to record the data via Wi-Fi. Works well....
RobinScurr is offline   Reply With Quote
Old 28-01-2019, 14:50   #12
Registered User

Join Date: Dec 2017
Posts: 8
Re: Bottom contour mapping via a dinghy

Most of the major names have a contour mapping "fish finder" these days.

Saturday morning fishing shows are great for this info. Even my electric motor has a built in GPS.

https://www.westmarine.com/WestAdvis...n-Contour-Maps

https://www.lowrance.com/lowrance/type/mapping/

Old_Geezer is offline   Reply With Quote
Old 28-01-2019, 15:01   #13
Registered User
 
Scaramanga F25's Avatar

Join Date: Mar 2015
Posts: 716
Re: Bottom contour mapping via a dinghy

For this purpose, I use my handheld depth sounder.

Walmart $ 67. oo Price doubles + in marine stores.
Vexilar if I remember.
Scaramanga F25 is offline   Reply With Quote
Old 28-01-2019, 15:08   #14
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 2,527
Re: Bottom contour mapping via a dinghy

I like to anchor in remote places in Alaska and Canada. Some places haven't had new surveys in 100 years. And some places had the bottom raise after the 1964 earthquake. I use a spare Furuno depth sounder in a small boat to sound out entrances and prospective anchorages before I risk the big, wood boat. The sounder along with a gps plugin and my laptop adds the new depth after I've corrected for the tide state. Enough passes and I've found all the rocks and shallow spots. Sometimes I can find a natural range and in a few places I've made rock pile ranges so I can visually stay in safe water and go back year after year.
After that, it's quiet and I have nobody bothering me.
Lepke is online now   Reply With Quote
Old 28-01-2019, 15:27   #15
Senior Cruiser
 
Dave_S's Avatar

Cruisers Forum Supporter

Join Date: Jun 2016
Location: Brisbane Australia
Boat: Schionning Waterline 1480
Posts: 1,263
Re: Bottom contour mapping via a dinghy

Navionics can update your maps as you run around in your dingy if you are in WiFi range or buy a sounder that will take your Navionics chip and update it directly. You can chose to share these maps with Navionics or not.

I assume Navionics will want to see repeated information from multiple sources to use the information.

In areas frequented by boats I would always share but I think in uncharted areas I would only share if there was a danger.

http://www.navionics.com/usa/charts/...onarchart-live
__________________

__________________
Regards
Dave
Dave_S is offline   Reply With Quote
Reply

Tags
dinghy

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Trimaran Contour 50, Nootka 50 or Hammerhead 54? freetime Multihull Sailboats 22 25-09-2014 13:54
GPS + Sounder = Bottom Contour? F51 Marine Electronics 12 26-05-2014 14:49
Bottom Mapping Issue with MaxSea 10.3.2 Lobster Fisher Navigation 0 15-04-2010 16:10
GPS MAPPING for cars...why not boats? Chief Engineer Marine Electronics 13 04-02-2008 09:50
Article re NOAA charts & mapping programs Gerald Simons Navigation 7 14-11-2003 08:38

Advertise Here


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:55.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×

ShowCase vBulletin Plugins by Drive Thru Online, Inc.