Power Boat Capsize?

[belizesailor]

Originally Posted by Adelie

...
2. Lots fewer recreational powerboats making long offshore passages so likelihood of being hit by overpowering waves is much lower on a global scale.
...

Yes, way fewer power vessels out cruisng. Most power boaters I know stick pretty close to home and favor fair weather. So less likely to get into severe weather and thus fewer incidents to report. Need a stat based on % of type of cruising boats to really compare.

[AnchorageGuy]

Originally Posted by darylat8750

There was a semi planing trawler style boat (about 48 ft I think) sunk in the N.A. River system within the last year or so. In a shallow area a large tow sucked enough water out from the edge of the river that the small boat grounded, leaned over far enough that the boat foundered before it could refloat. Lawyers are still involved so we haven't heard the whole story yet. Maybe not applicable to this question but interesting.

Here is a report on the capsize of the trawler on the Tenn Tom. This is a member of one of our boating organizations. Cause of trawler capsize unclear . Chuck

[hpeer]

The Ryan’s Commander capsized off Spillars Cove, near Bonavista, on September 19, 2004. In the tragic wreck, two brothers were lost: Dave and Joe “June” Ryan.

Ryan's Commander

The Ryan's Commander
The Ryan's Commander was a 65' Newfoundland small fishing vessel (NSFV) which sank as a result of the loss of stability, capsizing in 2004 off the coast of Newfoundland, Canada. The design of the vessel, as well as some of the assumptions made of the vessels apparent stability before delivery, have raised questions of ethics, regulations, and practices in light of the loss of life and the vessel itself.

Ryan's Commander - Narciki

Pic of a similar boat....Arctic Leader

[hpeer]

Last spring I was eves dropping on our Marina Manager giving a weather briefing to a few power boaters who were prepping to cross the Delaware Bay from Delaware City to Cape May. I really thought he over did it, until is at down and thought it through.

These guys were mostly doing the Great Circle and none had been on such an exposed bit of water before. Yes the Chesapeake, but that has more places to seek shelter and less current

Anyway, looking at the height of the fly bridge, and the draft, it is easy to see that these guys could, if handled poorly, go over. They will likely get at least a rough ride.

I suspect fewer power boats, trawlers, etc. turn turtle because they are less exposed that sailboats, they stay inshore. There is a 65 footer with 4-1/2' of draft sitting in the yard right now. Double decker with a fly bridge.

Someone above mentioned sea height and boat length. That is probably from some studies after Fastnet and is described in Coles Heavy Weather Sailing.

[mrohr]

Maybe 5 years back, a cabin cruiser flipped here near West Point in flat water when she was driven going fast into shoaling water and skipper put her hard over as he recognized his mistake;resulting capsize trapped some below decks in + - 4 feet of water and at least one drowned. Bottom was very sticky mud and suspect craft had a deep v bottom but it would be interesting to know the physics that caused this tragedy on a pleasant summer day.

[Sand crab]

Originally Posted by hpeer

Ryan's Commander - Narciki

Pic of a similar boat....Arctic Leader

And no one thought this boat may not be stable.

[Steadman Uhlich]

Here is a quote from an article in Yachting mag

"We often think of the size and steepness of waves as being the deciding factor in capsize (along with a vessel's inherent stability characteristics). But research suggests that the most significant factor is whether a wave is breaking or not. No matter the strength of the wind, the wave height or its steepness, it only takes a breaker to knock a boat over - and that wave does not need to be very large.
Research a decade or so ago by the Wolfson Unit at University of Southampton University concluded that for a 10m yacht, ‘you only need a breaking wave of 3m to pose a risk of capsize'.
Various types of boat and keel type were tested. A wave height of 60 per cent of the boat's length capsized all the models they tested. So just to spell this out, a 32-footer would almost certainly be capsized a breaking wave with a height of as little as 20ft.

Read more at Capsized by a breaking wave | Yachting World

[MarkSF]

Originally Posted by Steady Hand

Here is a quote from an article in Yachting mag

"We often think of the size and steepness of waves as being the deciding factor in capsize (along with a vessel's inherent stability characteristics). But research suggests that the most significant factor is whether a wave is breaking or not. No matter the strength of the wind, the wave height or its steepness, it only takes a breaker to knock a boat over - and that wave does not need to be very large.
Research a decade or so ago by the Wolfson Unit at University of Southampton University concluded that for a 10m yacht, ‘you only need a breaking wave of 3m to pose a risk of capsize'.
Various types of boat and keel type were tested. A wave height of 60 per cent of the boat's length capsized all the models they tested. So just to spell this out, a 32-footer would almost certainly be capsized a breaking wave with a height of as little as 20ft.

Read more at Capsized by a breaking wave | Yachting World

Those wave heights are all on the beam, of course. Which is why active steering techniques in a storm are important.