shallow water sailing electronics

Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Sounds expensive. :)
The iPad is around $700, the case is $50, sonar phone is $149, the mount was $40 and the 12 volt outlet was $35. So for under $1000 you have an integrated chart plotter with sonar and fish finder. Plus you can use the iPad for other stuff.

Oh, add another $50 for the app.
 
May 24, 2004
7,129
CC 30 South Florida
In shallow water it is not if you are going to hit bottom but when. Talk to other boaters in the area and get some valuable information like what is the bottom composition of the lake, how do the shores slope up, are there any obstacles and what is their approximate location, water level fluctuations, etc. A depth sensor is set to measure the depth of the water and not the proximity to an obstacle in your path. Navigation charts give you a surveyed depth of the lake as of the dates the survey was conducted. A depth meter is an invaluable tool as it allows you to know the distance from the bottom of the keel to the bottom and whether it is increasing or decreasing. It allows you to perform your own individual survey of the places in your sailing area. It is your keel or center board that will likely find the bottom first so finding out at what depth does your keel touch bottom as indicated by your depth meter is the most important reading you will need. On a calm day and in an appropriate area with a soft bottom go ahead and slowly bump the bottom on purpose and take a reading. I usually tack on an additional six inches and will make that the minimum water depth that I will intentionally approach. You do not have tides to contend with but you will have varying water levels. Understand that your charted or surveyed depths will be affected by the water levels; do always take a reading at your launching spot to compare against your historic base figure and this will allow you to know whether the level is higher or lower so you may adjust the charted depths. Learn how to read depth by how light reflects in the water, with practice you can approximate actual depth but most important be able to timely detect some obstructions.
In known or suspected shallow areas do operate at a very slow speed. It is not the grounding that causes damage it is the speed at which you ground that will determine it.
Do you homework and read about the different techniques to free the boat in case you get stuck. Know your boat as the type of keel whether fixed or retractable or whether ballasted or just a center board will determine how to act and just how careful you may need to be.
 
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JTulls

.
Dec 6, 2014
89
International 14 and J-Boat J80 San Diego
One route would be to buy the depth sounder and associated displays, etc for it, but maybe a good first step is to take a look at the charts for the area you're boating in and get familiar with the trouble areas.

The Navionics app is a great, cheap option -- you can go the route of buying the sonarphone and Tbox vexilar unit to get the depths, but even just the app (upgraded from the free version) will give you access to the SonarCharts and community edits. What that means is that if any sonar logs have been submitted for the areas you sail, Navionics will verify the data and then push updates to the maps, so you're getting crowd-sourced data instead of a standard issues paper map. You can also set the safety depth so the coloration changes to give you an easy heads up -- and I believe with the 'advanced mapping options' you get more control over the depth shading and it accounts for tidal/lake level fluctuations.

Just my two cents -- a depth sounder will be necessary eventually, but this is a quick/easy solution to get you out on the water!
 
Jan 18, 2015
20
MacGregor 26S Big Stone Lake
One route would be to buy the depth sounder and associated displays, etc for it, but maybe a good first step is to take a look at the charts for the area you're boating in and get familiar with the trouble areas.

The Navionics app is a great, cheap option -- you can go the route of buying the sonarphone and Tbox vexilar unit to get the depths, but even just the app (upgraded from the free version) will give you access to the SonarCharts and community edits. What that means is that if any sonar logs have been submitted for the areas you sail, Navionics will verify the data and then push updates to the maps, so you're getting crowd-sourced data instead of a standard issues paper map. You can also set the safety depth so the coloration changes to give you an easy heads up -- and I believe with the 'advanced mapping options' you get more control over the depth shading and it accounts for tidal/lake level fluctuations.

Just my two cents -- a depth sounder will be necessary eventually, but this is a quick/easy solution to get you out on the water![/QUOTE
Thanks. These forums continue to amaze me. The time and talent shared is outstanding.
 
Jun 8, 2004
10,024
-na -NA Anywhere USA
As a former dealer, I use to instruct my customers electronics is fine but when too much emphasis is placed on them at times I saw when my customers were spending too much time on them instead of looking around and forward would have grounded and/or hit other boats/people and so on.

Best advice, ask the locals, not the weekend warriors, for the local knowledge and have a chart with you so any issues can be pointed out. Never sail/motor at night unless you know the waters well. As for inland lakes, depth is easy most of the time to tell. If there is an island, shoreline, look at the elevation how the land lays. If steep at the shoreline, you have a good depth but if shallow, think of that with the land extending out from shore with a minimal depth for some distance. True with an island as well.

Too often I saw folks rely too much on electronics. Here is a good scenario. What if you crossed over the Chesapeake Bay Bridge Tunnel at the entrance to the Chesapeake Bay from the Atlantic Ocean at dusk about a mile or two past that, fog sets in and all of a sudden your electrical goes out along with the electronics and it is itch black. I always taught my customers as a back up to carry an AM Radio, flashlight and local charts and/or state highway road map with them knowing where the major AM stations are broadcasting from. Turn the radio until you have the strongest reception from two if not more stations and crossplot that on a map. It works and it used to be called RDF in the old days. This actually happened to me and I was able to come within 500 feet of Willoughby Spit at Norfolk next to NOB(Naval Operations Base) in the fog all the way. But in this case, we are dealing with a lake. Still applies

Most sailors as a good example will not run the Dismal swamp canal nor the Alligator River ICW at night. I did once at the behest of the owner on a Catalina 387 on the Alligator River ICW at night and it took everything out of two experienced sailors just to navigate that. I did it once and will never do it again.

As for attaching a depth sounder to the hull, Kermit made me a believer that plumbers putty does work. Kermit advise on that if you are reading this. I find it easier than epoxy, mineral bath solutions, and so on. The key to that is to prep and clean any surface and when inserted, insure there are no air bubbles. Give it time to set up
 
Aug 7, 2011
496
MacGregor 26S Lakeland, FL
Also, a couple notes specific to your boat...
1. Your swing keel will kick up if you get into shallow water, and other than rubbing damage, is usually safe. Underwater stumps and logs and old cars and such, well, you are on your own... ;)

2. Because of the water ballast tank in your 26S, you will probably not be able to mount any transducer internally in the front of the boat as the earlier poster had mentioned. The ballast tank goes too far forward and you can't reliably get to the bottom of the hull from the inside. This also applies to thru-hull mounting. There just isn't a good central location. You could, and some have, mount it off center, but that is not ideal. Most of us with boats like yours mount it in the forward part of the lazarette in the center, or on the transom outside. Yes, that's in the back of the boat, but again, as others have said, electronics don't take the place of familiarity with the local waters.

These boats can be beached safely and easily, so running aground on a sandbar or shoal is less worrisome to most of us. Many Mac26 owners have also learned how to blow the ballast with a small 12V inflator to raise the boat if grounded, then once off the sandbar, open up and refill the ballast and be on their way... Kinda neat feature specific to your boat.
 
Jun 8, 2004
10,024
-na -NA Anywhere USA
If I recall but not sure which model of the Mac 26, the centerboard had holes in it to allow water inside. Not sure why they did that but hitting anything with the centerboard is not good unless soft sand or mud. However you are in shallow water at that point and would recognize that. As for beaching any boat, sand is like that of sandpaper and over time will wear the gel coat off on the bow. Yes there is a bow guard you can put on but sure looks funny.
 

walt

.
Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
I have a 26S with the centerboard with the "holes in it" that allow it fill with water and sink. This boat is now 25 years old (wiith the original centerboard) and mostly sailed on inland lakes where water levels vary and I have whacked that centerboard more than a few times on rocks. One time my son "really" whacked the centerboard on a rock while I was in the cabin - very loud and scared the crap out of me.. which did leave a mark on the centerboard leading edge but that was it. Yep, not good to hit the centerboard on a rock but the one I have still works just fine after all the bad stuff I have done to it and whatever had happed to it during the previous 17 years of ownership.

And like Viswhiz said you can blow the ballast and get off a sand bar if you get stuck. One time sailing on a high mountain lake got my bearings mixed up and thought I was sailing through a channel and ran the boat onto a sand bar at full sailing speed. Boat was very stuck (centerboard just rotated up into the trunk and rudder released when this happened). I was single hand sailing, dropped the sails, got out a manual mattress air pump and blew out a bunch of ballast which can float the boat a few inches higher (also useful for trailer loading), got off the boat and pushed it off the sand bar.
 
Nov 19, 2011
1,489
MacGregor 26S Hampton, VA
It doesn't have "holes", it has a valve. The holes you may be thinking of are access to the keel bolt.

In a lake you are not going to have the tidal changes that you would in say the Chesapeake bay for instance so you won't be able to wait for high tide. Your keel doesn't lock down so it will swing back unless you are anchored and drift back into it.

The keel however is not lead or cast iron so it can be damaged by tree stumps if the lake is man made. Proceed slowly in shallow areas.

You can get navionics for a smart phone or one of many other apps but yes, do get paper charts until you learn the lake. Spend a little time reviewing your plan on the chart and set no go zones for your electronics. I have a Garmin 441s and it does fine but no matter your choice, the current depth is where you are, not what's ahead. They run around 400. It will show the lines and if an obstacle is reported it should be there, or at least you need to assume it is. Who knows, you may be the one who finds a new one.

Like I said proceed slowly in new areas. It's not a race. (A race is usually in safe areas) although I do not race, per set, I have found any time I am heading in the same direction as another sailboat... It's on! Haha. (And I usually lose).

It's a great boat and very forgiving. Remember one thing though. If your keel hits, your rudder is next. Set it up to kick up as well either by having a resale cam or shear bolt. When that happens, mark it on your charts and plotter!

Have fun!
 
Aug 17, 2013
816
Pearson P30 202 Ottawa/Gatineau
I know this is an old thread but I'm wondering if anyone still uses the vexilar sonarphone on their sailboat, looking at getting one and was wondering what you all think of it
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
I know this is an old thread but I'm wondering if anyone still uses the vexilar sonarphone on their sailboat, looking at getting one and was wondering what you all think of it
We are not using ours anymore. Nothing wrong with it. A young couple was getting their boat ready for cruising so we installed it on their boat. So it is still in use. I was just less interested in sharing data with Garmin after the active captain thing.
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
I know this is an old thread but another suggestion to help with the underwater obstruction awareness is that in addition to lake navigation charts or gps charts is to get local "fishing charts". These will show areas of stumps, ledges and other things that the fishermen use pick the best place to fish and it will give you some idea of possible trouble areas. As capta said, look at the shoreline but if the shoreline rises quickly on the outside shoreline of the lake it probably means that for a manmade lake, there may be mounts between the shoreline that don't quite come to the surface. Some of those islands Capta mentioned might be just below the surface. Think "if it was hilly here before they formed the lake, the bottom is still probably "hilly".