Keel offset for depth sounder

[Just Limin']

What do you set the keel offset to, on a Ranger 25 SC?

And, probably a stupid question, but once set, am I correct in then interpreting the dept reading to mean that's how much water I have below my keel?

I'm probably confusing my self.....

Thanks

 

[Irish Mist]

I set mine up to tell me the total depth of the water. I used a measuring tape in shallow ( 4-5 ft ) water and adjusted it until it was right. I do think most like to know how much water under the keel . With no offset it should be reading the depth from where ever the sounder is to the bottom. If you know the draft of the boat, use the tape measure to get the water depth, then subtract your draft and adjust accordingly .. I just know I should not go below 3 ft.. ( my draft is 30 inches ) but ideally you should always allow double your draft if possible , to be safe...Hard in Florida coastal cruising 🙂
Good Luck

 

[knotflying]

Determine the depth of the water you are in with a tape measure or put a weight on a string and lower it to the bottom. Then retrieve it and measure the length. Now see what depth you are reading on the depth sounder. The difference between the two will be your offset to get to te accurate water depth, which is the length of the string you just measured. I prefer to know water depth and know that I need 26". I set my alarm at 4 feet.

 

[stwendl]

The sensor is an I hull sensor to starboard side of the shaft but higher then the shaft ( at least on an r27 2015) roughly below the trim tabs. The draft of those boats are almost 3 feet and I always would err on the larger side due to wave action and uneven bottom as well as inaccuracies of the sounder.

Using offset or not is a religious subject and really more useful if you have drafts of several feet. Leaving at 0 with our boats is ok as long as the operator knows what the draft is. If you have multiple people using the boat I would enter the draft along with a savety margin to avoid that error🙂