Have your life boat ready to step into before the sailboat actually begins to sink but wait until it's actually sinking in the water before you hop on. Saying it like is that harder to put into a fortune cookie and doesn't read nearly as clever.
Self-righting keel question
- Thread starter Mossy Dell
- Start date
Awww. Fun.subject -too bad it's so old!
One thing I didn't see anyone pointing out and that no advertisers ever.bring up is...
If you are in weather big and bad enough to turtle you, it's not gonna be calm.
I know that sounds self evident but soooo many arm chair sailors seem to forget that a sea with a wave big enough to flip you will keep moving the boat around in extreme ways.
Which means it doesn't need to "right " itself from.some specific angle. Rather it only needs positive buoyancy and a heavy.keel.
Releasing all sheets certainly helps a good righting boat.to pop back up too!
ps.
The ideas behind multhulls was that you'd passagemake faster and be less exposed to adverse risk of this to begin with.
One thing I didn't see anyone pointing out and that no advertisers ever.bring up is...
If you are in weather big and bad enough to turtle you, it's not gonna be calm.
I know that sounds self evident but soooo many arm chair sailors seem to forget that a sea with a wave big enough to flip you will keep moving the boat around in extreme ways.
Which means it doesn't need to "right " itself from.some specific angle. Rather it only needs positive buoyancy and a heavy.keel.
Releasing all sheets certainly helps a good righting boat.to pop back up too!
ps.
The ideas behind multhulls was that you'd passagemake faster and be less exposed to adverse risk of this to begin with.
Here is a good article on stability:
Here is a graphic from the article comparing an Island Packet (blue) to a Tartan (red):
The higher righting moment of the Island Packet to the left shows that it will resist heeling about twice as much as the Tartan. The Tartan reaches vanishing stability at 120 degrees (where the red line crosses zero), while the IP is around 133 degrees (blue line crosses zero).
Extensive tank tests show that these curves are not so relevant in preventing a capsize. All hull shapes will capsize when struck on the side by a breaking wave higher than the beam of the hull.
The curves are critical for recovery from capsize (assuming the cabin is watertight.) The IP only has to tip over 43 degrees (180 less 133) in the waves from the inverted position to return to upright. The Tartan would have to roll over 60 degrees (180 less120) from inverted for the same result. The shallower depth of the IP curve on the right (inverted) side also means it takes half the rolling force from a wave to get to positive stability.
Here is a graphic from the article comparing an Island Packet (blue) to a Tartan (red):
The higher righting moment of the Island Packet to the left shows that it will resist heeling about twice as much as the Tartan. The Tartan reaches vanishing stability at 120 degrees (where the red line crosses zero), while the IP is around 133 degrees (blue line crosses zero).
Extensive tank tests show that these curves are not so relevant in preventing a capsize. All hull shapes will capsize when struck on the side by a breaking wave higher than the beam of the hull.
The curves are critical for recovery from capsize (assuming the cabin is watertight.) The IP only has to tip over 43 degrees (180 less 133) in the waves from the inverted position to return to upright. The Tartan would have to roll over 60 degrees (180 less120) from inverted for the same result. The shallower depth of the IP curve on the right (inverted) side also means it takes half the rolling force from a wave to get to positive stability.
I read the original posting and the responses and I was only left wondering if there was a reason for the question or if it was merely an academic inquiry with no specific purpose for boat evaluation.