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S&S Swan General - Swan 48 Freeboard marks
11 December 2019 - 19:26
Join Date: 11 November 2010
Posts: 18

Swan 48 Freeboard marks


During coding renewal the surveyor had an issue with the Freeboard measurements from the stability book of Snow Wolf (hull 38). The 1.171 metres specified in the book is below the waterline with a lightly loaded yacht!

Any other Swan 48 owners willing to share their stability booklets or give me the Freeboard measurements?



13 December 2019 - 12:40
Join Date: 02 January 2008
Posts: 1547

Dear Snow Wolf

Your freeboard mark measurement must be a mistake, but the MCA coding is not valid until you get this corrected. Ask the surveyor for a new reduced measurement.
Technically, Snow Wolf exceeds the MCA stability requirements with a big margin, and moving the mark up a bit - allowing the boat to sink deeper in the water - does not reduce the stability appreciably.
The freeboard mark rule comes from cargo ships, where it is strictly forbidden to load the ship deeper than the mark, because the stability then goes down too much, and there is a risk of capsizing.
The MCA rules require freeboard marks for boats over 15 m length, but Snow Wolf is likely to be a little shorter
Kind regards

14 December 2019 - 19:08
Join Date: 02 January 2008
Posts: 1547


Would it help if I send an ORC Stability and Hydrostatics Datasheet for your yacht, based on a previous inclining test, and showing that the Limit of Positive Stability is

132.6 degrees?
Kind regards

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