Where to set depth finder alarms?

tmh

Lieutenant Junior Grade
Joined
Aug 16, 2006
Messages
1,136
I just installed a depth finder and it has high/low water alarms I can set. Just wondering where most would set the low water alarm? 5 ft? 8 ft? I have a 19' bowrider I/O alpha one of that matters. The depth probe is in the rear (bilge). Thx.
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: Where to set depth finder alarms?

There is to much shallow water here to worry about it :)


But i would find out how close it is to real depth , many time mine will read 1 ft when there is 3 or more :rolleyes:

Tommays
 

Scout Sport Fish

Petty Officer 2nd Class
Joined
Apr 23, 2007
Messages
197
Re: Where to set depth finder alarms?

When do you feel like you should be alarmed? Haha. I personally set mine to 2 ft.
 

tnduc

Petty Officer 1st Class
Joined
May 2, 2007
Messages
292
Re: Where to set depth finder alarms?

What is your draft? I would add a few feet to whatever your draft is and set the alarm there.
 

bekosh

Lieutenant
Joined
Apr 27, 2004
Messages
1,382
Re: Where to set depth finder alarms?

I just installed a depth finder and it has high/low water alarms I can set. Just wondering where most would set the low water alarm? 5 ft? 8 ft? I have a 19' bowrider I/O alpha one of that matters. The depth probe is in the rear (bilge). Thx.
It depends on where you boat. Some places 10ft is considered shallow. Where I boat on Lake Winnebago, anything over 5ft is deep water. ;) If I set mine to 8 ft it would be going off all the time. I set mine for 3 ft. At idle that is just when the drive will start to hit if it is down all the way. If I'm on plane that tells me to put the hammer down and keep going.
But i would find out how close it is to real depth , many time mine will read 1 ft when there is 3 or more :rolleyes:
Tommays
Sounds like you don't have your keel offset set. It's reading the depth from the transponder not the water surface.
 

thurps

Chief Petty Officer
Joined
Jan 14, 2007
Messages
538
Re: Where to set depth finder alarms?

Shallow water alarms in my opinion are only good for fishing depths. In the ocean and lakes around here the water depth will be 40' then 6 in. By the time your alarm sounds, your dragging the bottom. Nothing like charts and knolage of your waters.
 

gstanton

Chief Petty Officer
Joined
Jul 3, 2003
Messages
451
Re: Where to set depth finder alarms?

I set mine at 4 ft. My draft is 2 1/2. Mainly use it when we are anchored and I'm either reading, fishing or planning on sleeping. That way, if the anchor looses its bite and we drift, it will get my attention. Otherwise, like has been said, it's area knowledge and experience.
 

WAVENBYE2

Lieutenant Commander
Joined
Apr 28, 2007
Messages
1,636
Re: Where to set depth finder alarms?

If it is a matter of the boat floating adrift while you sleep, look at what it is when your bow/stern snugged up and secure and then set it 2-3ft. deeper than what your current depth is. Mine is set on the stern also just so I don't run my stern aground while beaching. The lake that i go to goes from 0-100ft. with in 15 feet from shore in most areas.
 

bassboy1

Lieutenant Commander
Joined
Jun 23, 2006
Messages
1,884
Re: Where to set depth finder alarms?

I don't generally set alarms. My boat drafts 1 foot below the sounder (bout 1 1/4 - 1 1/2 from surface) and when it gets to 3 feet, then I watch it, and if it starts getting shallower, I drop to idle, at about 1 1/2 I make a judgment call as to keep going or stop and pull out the paddle. BTW, my boat won't plane, so slowing down actually decreases my draft as the nose goes back down, and the back comes up a bit.

Two weeks ago, when we were in NC, we were in a rowboat lake, and the water temp was higher than normal, so we tried to find deep water to find trout. We set the alarm for 15, and I rowed back and forth to find the channel. Keep in mind this lake is closer to a square mile, and we had a bit of trouble finding deep water. At areas we thought were closer than ten, we were reading three. i put in about 2 miles of rowing that day. And of course the wind changed directions when we decided to head back to the ramp, so I had a head wind and white caps BOTH WAYS. Wat da he!!?
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,755
Re: Where to set depth finder alarms?

Thurps is right. With the transducer in the rear and running at speed, you are aground before the sounder can alarm you. Some reefs and shelves are nearly vertical so in an instant you can go from 40 or more feet to inches. I've had the be-jeepers scared out of me in the middle of a very large lake in just that scenario. I'm watching the locator go from 20 - 90 feet so I'm fat dumb and happy cruising at 30+ across the lake. I look around a bit and when I glance back at the locator I'm in 6 feet of water and the bottom is coming up fast. At four feet I cross the ledge and in a heartbeat I'm back in deeper water. If you are fishing you should be watching the contour anyway so the depth alarms are just an annoyance in my view..
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
15,375
Re: Where to set depth finder alarms?

My alarm is set at 3.5 feet which is the point where I?m just about ready to hit bottom with the motor.

I boat in tidal water so the depth of the dredged channel (4? MLW) coming out of the marina can vary as much as a couple of feet at any given time.

You can get a good indication of the depth by looking at the height of the water on the pilings but the channel does shoal from time to time and it?s nice to get that audible reminder if I?m occupied with other tasks while idling out the inlet.

As noted above alarms are useless for running at speed. A good chart plotter is the only solution for that problem, of course, assuming that the body of water you're running is even charted.:D
 
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