I get the concept of how it works and what it does, but what is the easiest way to identify how much to set the offset for?  

 The lowest part of the boat is the bottom of the lower unit, and it's easy to measure from the transducer to that.  

 

I think mine is set for 1 foot and I just know that when the display reads less than 3 feet, I'd better pay attention.  It's all about how you want to use it and your personal preference.

 

Measure from water line to transducer.

4 hours ago, MickD said:

 The lowest part of the boat is the bottom of the lower unit, and it's easy to measure from the transducer to that.  

 

I think mine is set for 1 foot and I just know that when the display reads less than 3 feet, I'd better pay attention.  It's all about how you want to use it and your personal preference.

 

 

3 hours ago, J Francho said:

Measure from water line to transducer.

 

My original post was not very articulate.  Here is a link to a video where someone uses the Water Offset feature to adjust for the water level changes of the actual lake.  What I am looking for help for is how do I figure out how many feet the lake has actually changed so I can set the Water Offset accordingly.  If it is relevant, I have Helix 9 Mega SI G2N Fishfinder and Chartplotter.

 

 

 

We have a couple features.  So far I see three reasons to use it.  To get an actual depth of the water, to to gat an actual measure of keel to bottom, and to adjust loaded charts depth for varying water levels.

25 minutes ago, Happybeerbuzz said:

What I am looking for help for is how do I figure out how many feet the lake has actually changed so I can set the Water Offset accordingly.

USGS stores that data.

If I understand the question you are want to know how to get the information needed to set the offset.  For most lakes you can get the lake level online at http://www.lakelevels.info/  or from the web site of agency that manages the dam/lake.  If the lake level is different from summer pool then enter the difference.  You could also note the depth at a certain location,  say as you are leaving the marina,  and adjust the offset so that the map's contour depth matches the actual depth.  Personally,  I just make an educated guess based on the water level at the ramp if it's significantly different from summer pool.  The guy in the video was saying the water was 40ft below pool.  We don't see drops like that around here.  We do see lake levels that are 15 ft high sometimes.  I usually go somewhere else when that happens,  I don't like launching the boat in the parking lot. ? 

2 hours ago, Tennessee Boy said:

If I understand the question you are want to know how to get the information needed to set the offset.  For most lakes you can get the lake level online at http://www.lakelevels.info/  or from the web site of agency that manages the dam/lake.  If the lake level is different from summer pool then enter the difference.  You could also note the depth at a certain location,  say as you are leaving the marina,  and adjust the offset so that the map's contour depth matches the actual depth.  Personally,  I just make an educated guess based on the water level at the ramp if it's significantly different from summer pool.  The guy in the video was saying the water was 40ft below pool.  We don't see drops like that around here.  We do see lake levels that are 15 ft high sometimes.  I usually go somewhere else when that happens,  I don't like launching the boat in the parking lot. ? 

I just found the lake levels humminbird.com of the lake levels when they surveyed.  Combined www.lakelevels.info that you linked, I should be able to find the offset with a little math.  Thanks for your help.