Adventures with Stability.

[Stemar]

The true displacement of an old boat can surprise. My 1970 Snapdragon, with half a tank of fuel, little kit and no food or drink on board weighed in at 2.5 tonnes according to the lift in crane on Saturday. The published displacement is 1746 Kg. I'd expect other boats of a similar vintage to have put on a bit of weight as well.

 

[Tranona]

The true displacement of an old boat can surprise. My 1970 Snapdragon, with half a tank of fuel, little kit and no food or drink on board weighed in at 2.5 tonnes according to the lift in crane on Saturday. The published displacement is 1746 Kg. I'd expect other boats of a similar vintage to have put on a bit of weight as well.

More likely it is the published displacement that is wrong as it was probably an educated guess in the first place. Construction methods were such that even if the design calculation was reasonably accurate controls over manufacturing processes were poor.

 

[Uricanejack]

Under the impression this is about estimated or guesstimated stability on uncoded yachts

I just had a quick perusal of MGN 280 and the stability requirements which are for coded yachts.
Quite complex even having some knowledge of what the issue is about,

Just an idle question

How much stability is included in the RYA YM particularly onshore amd ocean?

It was news to me a yacht required a load line minimum freeboard and damaged stability

While our non coded vessels are fine with a rough guess, kick the tires, kick the tire light the fire and of we go.
Washing bikes kayakes and any other crap we feel like on deck

 

[zoidberg]

There is the mistaken 'urban myth' that the RYA's Shorebased Syllabus - Coastal Skipper and Yotmeister - is encyclopaedic and all-encompassing, which is nonsense. A moment's thought will show that a lifetime's learning and experience cannot be compressed into 40-odd hours of evening classes or a handful of online exercises.
It can only be a starting point and, like passing the DVLA Driving Test, is intended to be followed by much further study and learning.

Unfortunately, like the car Driving Test, many yotties cling to the view that, once they have a CS or YM certificate in their hands, they have become experts on most things boaty and highly-skilled in driving them. As we see on the roads and in the Solent, that's a very wrong assumption.

 

[Kukri]

Under the impression this is about estimated or guesstimated stability on uncoded yachts

I just had a quick perusal of MGN 280 and the stability requirements which are for coded yachts.
Quite complex even having some knowledge of what the issue is about,

Just an idle question

How much stability is included in the RYA YM particularly onshore amd ocean?

It was news to me a yacht required a load line minimum freeboard and damaged stability

While our non coded vessels are fine with a rough guess, kick the tires, kick the tire light the fire and of we go.
Washing, bikes, kayaks and any other crap we feel like on deck

I don't remember any.

My favourite page in my ex code 0 boat's stability book is "Departure Condition - Main Saloon Flooded". I know what it means, but I can't help a smile. Yes, she would still be stable. Just not very.