Depth sounders and settings

[Jim Seamans]

Over the last couple of years I've played around with the depth meter settings on our boat. At first I just let it default to the waterline which told me the depth. Then I tried setting it to a negative value to the depth of my centerboard which gave me the depth below the centerboard. At the later setting my wife would get upset due the shallow alarm going off at two feet, knowing that we were really in 8ft of water. Absolute depth for us is 2.5 to 3 of water so we can go very shallow.Soon we will be in a real keel boat that draws 5ft. How do you guys setup the depth meter?Actual depth or depth below the keel?JimS/V Java

 

[Justin - O'day Owners' Web]

Under the keel

I set my depth sounder so that the reading is offset to account for my keel. I would be simple matter to deduct the offset when using the boat, but I prefer the simplicity of having it spot on, especially when tired or stressed.Justin - O'day Owners' Web

 

[Steve Dion]

I prefer the actual water depth.

Jim:Unlike Justin, I prefer the actual water depth. I like it this way because it is easier (for me) to work with the charts when determining where we are. I know that anything less than 6 ft, we are getting into trouble.I know that many sailors do just as Justin does and set the keel offset into their systems.

 

[andy]

actual depth

true water depths can be an aid to navigation. I know not to go below 5' 6"

 

[Stu Jackson]

It Maybe Doesn't Matter

In lieu of trying to set the depthsounder to either of these two positions, I determined that the keel hits the bottom when the depthsounder says 4.4. It's simple.If you are always sailing in very shallow water, knowing keel offset or waterline calibration for sure is undoubtedly more helpful.For those normally sailing in deeper (usually) water, the difference between 0.0, 4.4 or 5.68934 is negligible.Once you know what it is "when you hit" is the key. You can find a soft sandy or muddy spot and give it a try to accurately "calibrate" your depthsounder.While "true" water depth is indeed a great navigational aid, with tides going up and down anywhere from 2 to 12 feet, being "close" is just as important as being within 0.0004657 inches.PS I'm also the guy who refuses to repair his fuel gauge - I work on engine hours at 0.5 gallons per hour. Hasn't failed in 4 years.

 

[Bill O'Donovan]

Depth below the keel

It's the absolute truth in terms of how far you can go, literally. It's also easy to check for accuracy, because when you actually "probe the surface," as they say in the Navy, you'll know for sure that when it says 3 feet you've touched. If your meter says 5 feet, however, you've got a calibration problem. If your meter says 1 foot, maybe you've lost the keel. I would suggest turning off the alarm and getting used to watching the depth meter for visual warning. Try to stay in 10 feet or more. You might also move the tilt-o-meter out of easy sight, since some people get spooked when they actually see that you're listing 20 degrees. "Ah, it's nothing, 5 degrees!"

 

[Geof Tillotson]

Actual Depth

Since ours is a centerboard boat, I use the actual depth. I don't mind doing the subtraction. Anyway, I have a rule, unless I want to ground the boat for maintenance etc. I keep her in at least 7 feet of water. BTW - Board up I need 2' 3", board down I need all 6 feet.Geofs/v Day-O

 

[Doug Rodrigues]

For me...under the keel.

Twice now I've hit bottom while slowly maneuvering toward a rocky bottom shore. I installed the Depth Finder to give me a little advanced notice and as an audio reminder to crank the keel back up.

 

[Dakota Jim Russell]

All can understand actual water depth <nm>

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[Claude L.-Auger]

Actual Depth Minus the Pilot's foot

Charts always show mean low water unless otherwise posted. I find it easier to set the sounder at actual depth, but I do recommend taking off 1 foot from the real actual depth.When you calibrate (preferably at your dock), use a lead line to get the real actual depth abeam of the closest possible place you can get to your transponder. Then set-up your sounder to show 1 less foot (The Pilot`s foot). That way, if someone else is skipping, when they call out the depth, you still have an extra foot to help you while you decide to take action before Lindsay's law grabs a hold of your keel. Good Luck

 

[Jim Seamans]

Thanks Everyone Very Helpfull

I think I'll try the actual minus 1 ft. I like the sound and depth of that. Maybe my wife won't freak out on meStory - Last time we were out I was relaxing on the stern seat and she looked at the depth and screamed that we were in four feet of water. Of course I looked over, while she was telling me to turn off, and told no problem we were in 40 ft. She did a double take and went back to her book.Jim

 

[Chuck Wayne]

depth finder setting

it's a personal preference- I prefer to put in the keel offset-when I'm navigating in deeper water, i can add in the 5'. in real shallow water, I'd rather not have to do the mental calc-when it says zero, I know i'm in trouble. BTW, I use this a lot! at mlw, I have 6" clearance in the channel into my marina!

 

[Wayneo]

by pennies worth

Actuall depth, then I don't have to worry about if I zeroed it with the board down or up. Thus, 3 feet and go slow with board up and 6 ft with board down. Just came back where my mooring was 3 ft at low tide and all went well.