myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website

Welcome to myHanse.com the forum for Hanse Yachts owners throughout the world.

Forum Home Forum Home > Hints and Tips > 445
  New Posts New Posts RSS Feed - Depth sounder offset
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Depth sounder offset

 Post Reply Post Reply
Author
Message
Matt View Drop Down
Commander
Commander


Joined: 08 March 2014
Location: New York, USA
Status: Offline
Points: 99
Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt Quote  Post ReplyReply Direct Link To This Post Topic: Depth sounder offset
    Posted: 14 February 2019 at 01:47
Can someone tell me the offset they have set on their depth sounder for the 445? I had a system issue and lost the setting. Many thanks in advance.
Back to Top
Mark&Catherine View Drop Down
Admiral
Admiral
Avatar

Joined: 18 January 2013
Location: Turkey
Status: Offline
Points: 1108
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mark&Catherine Quote  Post ReplyReply Direct Link To This Post Posted: 15 February 2019 at 08:32
this is a debate I have with my wife all the time.  I use no offset so that depth is very close to chart depth plus tide.  The small distance between the water and the actual sensor (20 centimeters or so) is insignificant in practice and gives me a bit of safety when in shallow water, where anything less than 2 metres means Iím going to touch.  She would prefer to set the offset to keel depth, and retain the same margin of safety when the readout says 0
385 ubulukutu sail number GBR 3350L in Turkey and Greece with Mark and Catherine
Back to Top
S&J View Drop Down
Captain
Captain
Avatar

Joined: 30 August 2014
Location: UK
Status: Offline
Points: 318
Post Options Post Options   Thanks (0) Thanks(0)   Quote S&J Quote  Post ReplyReply Direct Link To This Post Posted: 15 February 2019 at 10:29
I use +0.3 on my 385 and have verified this with a lead line.
I prefer to know the actual depth of water for easy reference to depth contours on the chart, although this is not quite as useful now I am back in tidal waters.
I set my depth alarm at 5m (or 3.5m in shallow areas like Chichester) so I get a bit of warning before touching!



H385 #351 Ningaloo UK south coast & Southern Ireland (2019)
Back to Top
Johny View Drop Down
Sub Lieutenant
Sub Lieutenant


Joined: 15 March 2016
Status: Offline
Points: 18
Post Options Post Options   Thanks (0) Thanks(0)   Quote Johny Quote  Post ReplyReply Direct Link To This Post Posted: 15 February 2019 at 14:33
The depth offset for the 455 is -1.67m in order to measure the depth under the keel. Probably similar for 445.
Back to Top
Matt View Drop Down
Commander
Commander


Joined: 08 March 2014
Location: New York, USA
Status: Offline
Points: 99
Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt Quote  Post ReplyReply Direct Link To This Post Posted: 16 February 2019 at 01:19
Thanks all. Like Mark I prefer water column depth than distance under keel so that I can navigate using depths. Where we sail now there are times where every inch/cm counts in places. I was able to get some measurements today and opted to use +1ft / 30cm which is slightly conservative but also allows for cruising load out.
Back to Top
Buggle View Drop Down
Sub Lieutenant
Sub Lieutenant


Joined: 14 February 2015
Status: Offline
Points: 4
Post Options Post Options   Thanks (0) Thanks(0)   Quote Buggle Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2019 at 22:51
To get the depth under my keel, I apply 0.6m offset for the depth sounder on my 2014 Hanse 445, using the keel drawings of Hanse.
Back to Top
Richard M View Drop Down
Captain
Captain
Avatar

Joined: 06 November 2006
Location: United Kingdom
Status: Offline
Points: 184
Post Options Post Options   Thanks (0) Thanks(0)   Quote Richard M Quote  Post ReplyReply Direct Link To This Post Posted: 16 June 2019 at 17:29
 I've had to have a reset on my system so the offset information has disappeared. Personally I prefer to know the actual depth of the water column but the rest of the crew want to read the depth beneath the keel, ie keel touches at zero. I've given up the argument.

As I read this string there seem to be somewhat different values from Buggle and Johny. Am I right to apply an offset (via the Settings page on the MFD) of minus 1.67 metres for a H455 standard keel to achieve this result?

Many thanks


Richard


Richard M

(S/Y BrightStar - H 455 #90; ex S/Y Providence - H 400e #290)
Back to Top
Johny View Drop Down
Sub Lieutenant
Sub Lieutenant


Joined: 15 March 2016
Status: Offline
Points: 18
Post Options Post Options   Thanks (0) Thanks(0)   Quote Johny Quote  Post ReplyReply Direct Link To This Post Posted: 19 June 2019 at 06:45
The Hanse manual for the 455 has two relevant pieces of data with respect to the calculation of offset for the depth. These are:
1. Standard T-Keel height is 1.67 m
2. Boat draught is approx 2.25m (the draught is the vertical distance from the water surface level to the bottom of the keel).
The depth sensor is installed approximately in line with the top of the keel (that is where the keel is attached to the hull). Therefore the calibration for the depth offset under the keel is -1.67 m
The distance from the water surface level to the sensor is the draught minus the keel height. 
Therefore the calibration for the true water depth is 2.25 - 1.67 = +0.58 m.
Back to Top
Matt View Drop Down
Commander
Commander


Joined: 08 March 2014
Location: New York, USA
Status: Offline
Points: 99
Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt Quote  Post ReplyReply Direct Link To This Post Posted: 20 June 2019 at 05:27
If you look up the keels on the Hanse Shop website they very helpfully include diagrams with measurements from DWL to keel head and foot. This is a new addition since I first asked my question and has proved definitive.
Back to Top
Richard M View Drop Down
Captain
Captain
Avatar

Joined: 06 November 2006
Location: United Kingdom
Status: Offline
Points: 184
Post Options Post Options   Thanks (0) Thanks(0)   Quote Richard M Quote  Post ReplyReply Direct Link To This Post Posted: 20 June 2019 at 06:08
Many thanks Matt!
Richard M

(S/Y BrightStar - H 455 #90; ex S/Y Providence - H 400e #290)
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.063 seconds.

Links : www.hanseyachts.co.uk www.hanseyachts.com www.fjordboats.co.uk www.dehler.co.uk www.varianta.co.uk