Beneteau 331 - Depth Finder Sensor Location

Does anybody happen to know the location of the sensor on this boat or how to find out where it is? Based on the specs, this boat has a 5.5 foot draft but we were sailing yesterday and the depth finder said we were in 3.5 feet of water so something is not right. I know we could have been in some super light sludge but it did not seem like that and nothing was churning up behind the boat so I am wondering if the sensor might not be at the water level?

I do not know where your transducer is located but it’s pretty common for them to be through the hull at a point forward of the keel, thus below the waterline. The number you need to know is the distance from your transducer to the bottom of your keel. Depending on the age of your depth sounder, you should be able to calibrate it so you have a more accurate reading. Otherwise, you have to do the math.
If the distance from transducer to keel bottom is 3 feet, and you were showing a depth of 3.5 feet, you had .5 feet clearance. (Assuming you do not have a shallow draft keel. Draft for those is reported as 3.33’.)

We calibrate our depth finder to show the depth beneath the keel. We get nervous when it gets down to .5 Yours might be set the same way, so that 3.5’ would mean no problem; you’re sailing in 9’ of water (5.5’ draft plus 3.5’ water= 9’.)