What floats your boat?

[Ships_Cat]

Re: Pros .....

Yes I agree, 10 cm is miles too much.

When one considers the canoe draft (draft without fin) of a modern fin keeled yacht will be considerably less than 1m (for yachts under say 45 foot) then the increased draft when going into fresh water is going to be of order of magnitude 1 cm depending on canoe draft and hull shape (1 m draft box would draw an extra 2 cm or so).

The 1/48 rule will be too high for modern fin keeled yachts and probably quite a bit high for older boxy shapes, and probably fine for modern ships as the rule applies to a box - in my view /forums/images/graemlins/smile.gif.

{SG water is approx 1.021. 1/0.021 approx = 48}

John

 

[Guest]

SW vs FW

SW is accepted at standard 1.025.

1/48th is the FWA stipulated for Merchant Vessels based on average calculations over years..... and now accepted for yonks as statutory allowance.

Using 1/48th will not lead to significant error - as the average yacht is not box-shaped and will actually rise / sink less than that due to the tumblehome and waterplane etc.
Of course being a sail-boat then it gets even worse - as the waterplane has a transverse factor also of heel .... increasing it further !!

Oh dear - who started this ??????