Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 22-09-2018, 08:22   #1
Registered User

Join Date: Dec 2013
Location: Leavenworth, KS
Boat: 1983 oday 22'
Posts: 842
Under What Conditions.....

Whenever I've been sailing on a catamaran, and the waves start to crash over the bow, I start to get a little scared about the boat flipping stern over bow (pitch poling, right?). I don't have this fear on monohulls because the deep heavy keel. But catamarans are so light... I think I get scared because I don't know enough about how much the cats can handle before flipping.

Can someone educate me on this? Is it virtually impossible (like on a monohull?) or is there a certain wave height that would cause this? Or is it when waves come up over half the cat? or maybe a specific angle? Does anyone have a recollection of this ever happening to a catamaran? perhaps an article?
__________________

scarlet is offline   Reply With Quote
Old 22-09-2018, 08:48   #2
Registered User

Join Date: Feb 2017
Location: Merritt Island, FL
Boat: Endeavour 51
Posts: 19
Re: Under What Conditions.....

I could be very wrong, but I think I read somewhere that you need very large waves to cause a boat to pitch pole. Something like the waves heights need to be 75% of boat length. 40 foot boat = 30 foot waves.
__________________

Kalimniosjohn is offline   Reply With Quote
Old 22-09-2018, 10:02   #3
Registered User

Join Date: Oct 2012
Location: Home for a couple of years.
Boat: Beneteau 49
Posts: 432
Re: Under What Conditions.....

I do not have numbers for you but I've been in some very nasty storms of New Zealand and the S. Pacific islands while on my Lagoon 450.

The whole trick is to control the boat speed. If the bow goes under and the sail has enough power to push the boat over, you are in trouble... So, reduce speed, hit the waves at around 45 degrees and you should be fine (not comfortable, just fine).

You also have to be extra careful just in case something breaks. If that happens, all bets are off. I was very conservative. During major bad seas, my target speed was 5-6 knots. You have to figure out a safe speed for your boat.

I'm sure others will give you more technical information.
boom23 is offline   Reply With Quote
Old 22-09-2018, 10:07   #4
Registered User

Join Date: Oct 2015
Posts: 832
Re: Under What Conditions.....

Quote:
Originally Posted by scarlet View Post
Whenever I've been sailing on a catamaran, and the waves start to crash over the bow, I start to get a little scared about the boat flipping stern over bow (pitch poling, right?). I don't have this fear on monohulls because the deep heavy keel. But catamarans are so light... I think I get scared because I don't know enough about how much the cats can handle before flipping.

Can someone educate me on this? Is it virtually impossible (like on a monohull?) or is there a certain wave height that would cause this? Or is it when waves come up over half the cat? or maybe a specific angle? Does anyone have a recollection of this ever happening to a catamaran? perhaps an article?

Some comments...

First is that monohulls can most certainly pitchpole--under the right conditions, of course some of them will right themselves afterwards.

Second, waves crashing over the bow do not cause pitchpoling. Surfing at high speeds down a wave, and then burying the bow in the back of the next wave is the cause. When the bow suddenly stops, and the back of the boat keeps going, that's a pitchpole.
billknny is offline   Reply With Quote
Old 22-09-2018, 10:13   #5
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 20,523
Re: Under What Conditions.....

I seldom had any waves over the bow in a 42 ft cat. Are you talking small cats, like Hobie's at high speed? or...? I did experience "slamming" under the bridgedeck. I wouldn't worry about pitchpoling in a large cat except in storm or very large seas.

The thing about cats is this: They seem stable and sailing mostly flat, even when over stressed, until suddenly, they go over. You get little warning.
I remember being caught in a sudden 40-45 windspeed with higher gusts and full sail up. My cat hardly heeled at all. I'm looking at the anemometer and thinking "really? I can't even tell the winds that high". Then with the help of a 6-8 ft steep wave it heeled fast. Fortunately, I was just about to dump the mainsail anyway at the time this occurred.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 22-09-2018, 13:00   #6
Senior Cruiser
 
44'cruisingcat's Avatar

Cruisers Forum Supporter

Join Date: Sep 2006
Posts: 8,192
Images: 69
Re: Under What Conditions.....

Quote:
Originally Posted by scarlet View Post
Whenever I've been sailing on a catamaran, and the waves start to crash over the bow, I start to get a little scared about the boat flipping stern over bow (pitch poling, right?). I don't have this fear on monohulls because the deep heavy keel. But catamarans are so light... I think I get scared because I don't know enough about how much the cats can handle before flipping.

Can someone educate me on this? Is it virtually impossible (like on a monohull?) or is there a certain wave height that would cause this? Or is it when waves come up over half the cat? or maybe a specific angle? Does anyone have a recollection of this ever happening to a catamaran? perhaps an article?
You've been spending too much time reading the alarmist nonsense on this forum.

You can pitchpole any boat, but the bigger the boat, the less likely. For a large cruising cat it would take extreme conditions.

To give an example, a crew racing on a ShawnArber high performance cat in a Brisbane to Gladstone race were sailing in 30 - 35 knots downwind with full main and a spinnaker, frequently reaching speeds over 25 knots.

They still didn't pitchpole, although they did bury the bows a few times, before eventually deciding to reef the main.

Cruisers in those conditions would have no main up, and maybe half a headsail. In a much lower powered boat.

And these days, many production catamarans are anything but light. Some are considerably heavier than many similar length monohulls. Not that that makes them any safer....
44'cruisingcat is offline   Reply With Quote
Old 22-09-2018, 14:35   #7
Registered User

Join Date: Jun 2012
Location: Port Aransas, Texas
Boat: 2019 Seawind 1160 Lite (build underway), Prev. 2002 Seawind 1000
Posts: 1,150
Re: Under What Conditions.....

Seawind 1000 (33 ft long cat), 150 mile long offshore race, 32 knots true wind, loose beat, double reefed main, 13-15 knots boat speed. Punching into waves that washed over the windows of the hard top, dumped into cockpit behind us, and drained. When the front windows went opaque with green water, you stepped forward under targa to avoid water dumping down collar of your fowl weather jacket. Everyone on the boat was seasick, including the two of us that took meds. The mast pumped a lot. The boat would decelerate a bit when we punched waves. But never, ever close to pitch pole. Biggest risk to me was dismasting. First place, Multihull C (big cat) division!

A Bahia 46 crossed the finish line about 15 minutes ahead of us. (They owed us a couple hours on time correction). At the marina, they parked in front of us, pulled out the water hose, and started washng the barf off of their stern!

In that race, about one-third of the monohull fleet dropped out, for those of you that think they fared better!
__________________

sailjumanji is online now   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Coolmatic cu 55 under performing under way. unbusted67 Electrical: Batteries, Generators & Solar 1 16-12-2014 13:22
Great tool for weather and sea conditions. Inthewind Navigation 1 03-05-2008 21:13
California Coastal Conditions... DefiantSix Pacific & South China Sea 12 01-05-2008 14:35
10 Deadly Conditions GordMay Electrical: Batteries, Generators & Solar 4 20-10-2006 20:49
HAMs Report Hurricane Conditions GordMay Atlantic & the Caribbean 8 03-10-2005 16:47



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 06:02.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.