What is the distance from the depth sensor to the top of the keel. Need data to set depth offset. This is a 44 Hunter-2004
Depth Offset
- Thread starter Wallace24042
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Measure from the toerail at the point on deck where the sensor is located to the water. From inside, measure from toerail height to the sensor. Subtract these two and subtract that result from the rated draft. This will give you the keel offset from the sensor. It should be draft(60")-18"= Offset(42"), where the 18" is the approximate difference.
My 2 cents.............
I'd much rather err on the side of caution when it comes to depth and running aground. I have mine set at 6' (my draft). I'll take the extra 18" too. So when my depth alarm beeps at me showing 5', I know I got about 5-6' under keel.
I'd much rather err on the side of caution when it comes to depth and running aground. I have mine set at 6' (my draft). I'll take the extra 18" too. So when my depth alarm beeps at me showing 5', I know I got about 5-6' under keel.
Offset
Wallace: I have the deep draft version of a 410, which I think is 6'4". I called Hunter and was told my keel is 3'2" tall. I then made the offset 3'4" so the depth readings record the water beneath the keel. I am remembering these numbers from several years ago and I'm pretty sure they are accurate. For your particular model, give Hunter a call. They will have a guy go out to the yard and measure a keel which is still in the crate which is what they did for me. John Richard s/v Jack's Place
Wallace: I have the deep draft version of a 410, which I think is 6'4". I called Hunter and was told my keel is 3'2" tall. I then made the offset 3'4" so the depth readings record the water beneath the keel. I am remembering these numbers from several years ago and I'm pretty sure they are accurate. For your particular model, give Hunter a call. They will have a guy go out to the yard and measure a keel which is still in the crate which is what they did for me. John Richard s/v Jack's Place
18inches to be added to keel depth
I suggest u rethink subtraction of the 18". Raythenon manuel indicates addition of 18 to say 5' for the offset. Therfore about 6' appears okay.
I suggest u rethink subtraction of the 18". Raythenon manuel indicates addition of 18 to say 5' for the offset. Therfore about 6' appears okay.
What about getting actual measurment?
Here on the Chesapeake with the usually gradual sloping sandy bottoms, one time when I could feel the keel sliding across sand I checked the difference between my depth guage and and my 5'0" draft and changed the offset to match. You could also anchor in a shallow spot, take accurate depth measurements with a boat hook or something and then adjust accordingly.
Here on the Chesapeake with the usually gradual sloping sandy bottoms, one time when I could feel the keel sliding across sand I checked the difference between my depth guage and and my 5'0" draft and changed the offset to match. You could also anchor in a shallow spot, take accurate depth measurements with a boat hook or something and then adjust accordingly.
It was weird, but worked.
A friend wanted to find the exact distance from the depth sensor to the bottom of the keel. So he setup a weird contraption the last time he had his boat hauled out. He didn't want to call Hunter, since every boat may be a bit different, and also since his boat is no longer in production, well.... He took 2 thin lines, tied to the toe rail on each side of the boat. He then tied a pole, like a boat hook, between the 2 lines underneath the keel. Think of it as a big swing. He made sure the pole was level and touching the lowest point on the bottom of the keel, then measured the distance of the line. He then did the same thing again right beneath the depth sensor and measured again. The difference between the 2 measurements is the offset.
A friend wanted to find the exact distance from the depth sensor to the bottom of the keel. So he setup a weird contraption the last time he had his boat hauled out. He didn't want to call Hunter, since every boat may be a bit different, and also since his boat is no longer in production, well.... He took 2 thin lines, tied to the toe rail on each side of the boat. He then tied a pole, like a boat hook, between the 2 lines underneath the keel. Think of it as a big swing. He made sure the pole was level and touching the lowest point on the bottom of the keel, then measured the distance of the line. He then did the same thing again right beneath the depth sensor and measured again. The difference between the 2 measurements is the offset.
Another method
I used another method for setting my offset. I took a tape measure and attached an old (already rusted) vice grip to the end (clamping across the tape, to avoid a "vice grip offset"). My dock was re-built after Isabel, and the whole area was re-dredged, so I assummed a fairly uniform bottom. I measured depth at a point abeam the depth sounder transducer, at the rub rail, and elsewhere around the bow of boat. Depths were uniform within a couple of inches, with the depths were read with the vice grip lying on the bottom and no slack in the tape. I reset the offset so as to allow the depth finder to read the observed average depth. The confidence in this method is dependent on one's confidence of the similarity of the depth directly below the transducer and the observed measurement made probably less than 5 feet laterally from the center of the transducer. Bolstering that confidence are the similar readings taken around the bow. This has worked well in that the observed readings are consistent with charted lwl depths and tide/wind influence, especially when leaving and returning to our marina across the long bar in Herring Bay (named Long Bar,for some reason). However, I consider this a stop-gap method at best, and intend to do a real measurement of the keel offset on the next haul-out to be accurate, using the info learned from the previous posts. -Hooper
I used another method for setting my offset. I took a tape measure and attached an old (already rusted) vice grip to the end (clamping across the tape, to avoid a "vice grip offset"). My dock was re-built after Isabel, and the whole area was re-dredged, so I assummed a fairly uniform bottom. I measured depth at a point abeam the depth sounder transducer, at the rub rail, and elsewhere around the bow of boat. Depths were uniform within a couple of inches, with the depths were read with the vice grip lying on the bottom and no slack in the tape. I reset the offset so as to allow the depth finder to read the observed average depth. The confidence in this method is dependent on one's confidence of the similarity of the depth directly below the transducer and the observed measurement made probably less than 5 feet laterally from the center of the transducer. Bolstering that confidence are the similar readings taken around the bow. This has worked well in that the observed readings are consistent with charted lwl depths and tide/wind influence, especially when leaving and returning to our marina across the long bar in Herring Bay (named Long Bar,for some reason). However, I consider this a stop-gap method at best, and intend to do a real measurement of the keel offset on the next haul-out to be accurate, using the info learned from the previous posts. -Hooper
No offset
Hey Hooper! Interesting concept to determine true depth. On my 34 I mesasured down from the waterline to a stick held level with the DF sounder head and now calculate that when the DF says 3 feet I should stop moving forward! That said, I was stirring up mud in Worton Creek Saturday when the DF said 4 feet-probably prop wash.
Hey Hooper! Interesting concept to determine true depth. On my 34 I mesasured down from the waterline to a stick held level with the DF sounder head and now calculate that when the DF says 3 feet I should stop moving forward! That said, I was stirring up mud in Worton Creek Saturday when the DF said 4 feet-probably prop wash.
off sets
I also have a 44DS and measured 3'0"from the sensor to the bottom of the keel before the boat was launched. You can set the offset where you want!
I also have a 44DS and measured 3'0"from the sensor to the bottom of the keel before the boat was launched. You can set the offset where you want!
My Take on this
When we first got our H356 I tried to set the offset to the bottom of the keel. But this kept freaking out the mate as to how much water was really there. She would see 3ft and think we were going aground. It would sometimes make me kringe forgetting it was water under the keel. I gave up and took several measurments with a tape to the bottom and then set my depth accordingly. When the depth says 9ft, I known I'm 9ft - no math in the head - gives me a headache. If I'm on a strange boat I always ask where the depth is set to. Jim S/V Java
When we first got our H356 I tried to set the offset to the bottom of the keel. But this kept freaking out the mate as to how much water was really there. She would see 3ft and think we were going aground. It would sometimes make me kringe forgetting it was water under the keel. I gave up and took several measurments with a tape to the bottom and then set my depth accordingly. When the depth says 9ft, I known I'm 9ft - no math in the head - gives me a headache. If I'm on a strange boat I always ask where the depth is set to. Jim S/V Java
too much math, a little common sense
What a great thread you all have going here! first, if I made my boat safe from my first mate "freaking out," I'd never leave the dock...water depth, heel, propane, wave height higher that 2 feet, winds more than 10 knots..the list goes on and on
I agree to err on the side of caution and set my offset to 5'6". the one and only time I went aground ( yes, folks, I'll admit it) the water under the keel was almost exactly 0 feet, which matches the spec draft of my 356. I rarely go into water less than 3 feet under the keel, and everyone who helms the boat understands offset. The extra few inches give me the benefit of time to make corrections. If I truly need to know the exact depth of the water, I look at my chart. Just an opinion.
What a great thread you all have going here! first, if I made my boat safe from my first mate "freaking out," I'd never leave the dock...water depth, heel, propane, wave height higher that 2 feet, winds more than 10 knots..the list goes on and on
I agree to err on the side of caution and set my offset to 5'6". the one and only time I went aground ( yes, folks, I'll admit it) the water under the keel was almost exactly 0 feet, which matches the spec draft of my 356. I rarely go into water less than 3 feet under the keel, and everyone who helms the boat understands offset. The extra few inches give me the benefit of time to make corrections. If I truly need to know the exact depth of the water, I look at my chart. Just an opinion.- Status