[C320-list] Depth Transducer Offset

[jbrown5093 at yahoo.com]

I agree with Warren. The other reason that I like knowing the true water depth is that it makes it easy when navigating by following depth contour lines on a chart or plotter. Reassuring to know that you're where you think you are without doing any math. Probably only important in the shallow water where we sail. The only downside is that there is some variation depending on the load in the boat and that variable is eliminated by using the water under the keel measurement offset-I think.
Jim Brown   "Desafinado"

Sent from my iPad

> On Jun 4, 2016, at 8:34 AM, Warren Updike <wupdike at hotmail.com> wrote:
> 
> Seems to me that when I look at the depth reading I want to know how deep is the water, period. I set the alarm at 5' to give some leeway. That way I don't have to add or subtract anything. Anyone at the helm will look at the depth and likely expect it to report just how deep is the water. Of course, we don't have much in the way of waves on the Chesapeake so our only real problem is the many shallows and mostly mud or sand.
> 
> Warren and Pattie Updike
> 1994 C320 "Warr de Mar" #62
> Middle River, Chesapeake Bay
> 
> -----Original Message-----
> From: Scott Thompson [mailto:surprise at thompson87.com] 
> Sent: Thursday, June 02, 2016 7:03 PM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] Depth Transducer Offset
> 
> Rick, I assume those are negative offsets. Otherwise your more 
> conservative readings are actually less conservative.
> 
> 
>> On 6/2/2016 5:52 PM, Rick wrote:
>> The depth alarm offset issue is a matter of which measure would you rather count on to avoid problems. How much risk is one willing to accept? A more conservative off set estimate might not consider always encountering flat water when entering a channel or one may consider a more risky proposition where the crest of a wave could provide one depth and the trough of that wave provides less depth under the keel. I found that on my Hull # 277 that the transducer is about 18-20 inches below the waterline just ahead of the keel while the depth at the keel is around 4 foot 3 inches below the normal waterline. Given the risk involved I found that having the offset alarm set at 3.5 or even 4 feet (plus 18- 20 inch transducer depth) provided me with an ample level safe measure where I sail. If one encountered moving sand bars or a more dangerous channel entry, I would increase the offset measure to 4.5 or even 5 feet with a 4 foot plus keel depth to allow for a deviation of an extra 1.5 to 2 feet below the keel to avoid  problems. How  much time or $$$ does one need to risk changing directions when running out of depth? Considering the damage that could be done to the keel, rudder and hull, which offset depth suits the size of your wallet?
>> Rick Sulewski
>> 1995 C320 hull # 277
>> 
>> -----Original Message-----
>> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of stepkap
>> Sent: Thursday, June 02, 2016 4:39 PM
>> To: C320-List at Catalina320.com
>> Subject: Re: [C320-list] Depth Transducer Offset
>> 
>> Hull 980 was set by the yard to -2.5 ft.
>> Steve
>> Saline
>> 
>> -----Original Message-----
>> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Daryl Hunt
>> Sent: Thursday, June 2, 2016 9:57 AM
>> To: C320-List at Catalina320.com
>> Subject: Re: [C320-list] Depth Transducer Offset
>> 
>> 
>> 
>> My offset is set to read depth below the keel, so it is specific to the hull #/year.
>> Fair Winds, DarylDaryl HuntC320 #660 BelievePultneyville, NY - Lake Ontario
>> 
>> -------- Original message --------
>> From: Chris Burti <clburti at gmail.com>
>> Date: 06/02/2016  12:08 PM  (GMT-05:00)
>> To: 320 <C320-List at catalina320.com>
>> Subject: [C320-list] Depth Transducer Offset
>> 
>> Did anybody happen to record and save the depth transducer offset number for their C-320? All the hulls are the same, so it doesn't matter what year/hull #.
>> Thanks,
>> Chris Burti
>> Commitment, #867
>> Farmville, NC
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