Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-09-2013, 11:42 AM   #1
TF Site Team/Forum Founder
 
Baker's Avatar
 
City: League City, Tx
Vessel Name: Floatsome & Jetsome
Vessel Model: Meridian 411
Join Date: Oct 2007
Posts: 7,332
Wind/weather and performance(FF)

I have noticed on my multilevel floating condo complete with oxygen tent above, that going against a good breeze along with it's associated chop(bay sea state) can cost me up to 2 knots. I went out yesterday and was traveling against wind and chop but WITH the tide and was doing 17kts(SOG) at my normal power setting. I made a 180 without touching the power and cruised back in at 19kts!!! I have always noticed quite a difference in speed at the same power setting but didn't think too much of it and probably wrote it off as a tidal thing. But I have recently realized this to be the case. My full enclosure(FF calls it the oxygen tent...and I always get a kick out of it) causes some pretty significant drag....sail area.
__________________
Prairie 29...Perkins 4236...Sold
Mainship Pilot 30...Yanmar 4LHA-STP...Sold
Carver 356...T-Cummins 330B...Sold
Meridian 411...T-Cummins 450C
Baker is offline   Reply With Quote
Old 11-09-2013, 12:34 PM   #2
Guru
 
Nomad Willy's Avatar
 
City: Concrete Washington State
Vessel Name: Willy
Vessel Model: Willard Nomad 30'
Join Date: Oct 2007
Posts: 18,743
Willy has a reasonably low amount of air drag and it shows. I've never increased power w my 40hp engine to compensate for head wind. The "oxygen tent" types may be a bit different but I suspect most all loss of speed is caused by tide flow.

When the wind gets up to 40 or so w 7' seas I always slow down because of the seas and always maintain plenty of headway. So w a low windage boat this is absolutely not a problem.
__________________
Eric

North Western Washington State USA
Nomad Willy is offline   Reply With Quote
Old 11-09-2013, 12:42 PM   #3
Guru
 
psneeld's Avatar
 
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,148
Quote:
Originally Posted by Baker View Post
I have noticed on my multilevel floating condo complete with oxygen tent above, that going against a good breeze along with it's associated chop(bay sea state) can cost me up to 2 knots. I went out yesterday and was traveling against wind and chop but WITH the tide and was doing 17kts(SOG) at my normal power setting. I made a 180 without touching the power and cruised back in at 19kts!!! I have always noticed quite a difference in speed at the same power setting but didn't think too much of it and probably wrote it off as a tidal thing. But I have recently realized this to be the case. My full enclosure(FF calls it the oxygen tent...and I always get a kick out of it) causes some pretty significant drag....sail area.
not sure if I'm being to nitpicky...but if you notice a 2 knot difference...could there be a 1 knot penalty and a 1 knot gain (like cruising into/with a current?

don't get me wrong...my sportfish definitely had a wind penalty with the hardtop/enclosure...

may want to recheck on a windless/currentless day for a more accurate measure if you care...it's not like you are really gonna change much as the enclosure is nice and your speed at that point won't make a huge difference except maybe for planning or trying to make a destination with low fuel.

when the REAL penalties and wind resistance shows up in ALL boats except subs.....is when you are probably slowing down for chop anyway.
psneeld is offline   Reply With Quote
Old 11-09-2013, 12:54 PM   #4
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Vessel Name: Carquinez Coot
Vessel Model: penultimate Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 12,559
A two-knot difference seems too large. Agree with psneeld that water current could be a factor if measuring speed over ground. Haven't noticed a drop in the Coot's speed with strong headwinds. Perhaps it helps to have a slow, low-profile boat to begin with. Do notice a list, however, with strong beam winds.

__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 11-09-2013, 01:00 PM   #5
Guru
 
psneeld's Avatar
 
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,148
Oh yeah baby..an enclosure can definitely slow you down 2 knots at high wind and boat speeds...did on my sportfish...

I was just curious about going with/against the wind...whether all penalty or half penalty and half assist.

Sure current is an issue but I'm hoping that issue was already though of.

Boat's like Coot and Willy will probably only see a major wind penalty when it's so strong that the waves are slowing you down even more..
psneeld is offline   Reply With Quote
Old 11-09-2013, 04:07 PM   #6
Guru
 
hmason's Avatar
 
City: Stuart FL
Vessel Name: Lucky Lucky
Vessel Model: Pacific Mariner 65
Join Date: Aug 2013
Posts: 2,760
Magic has a big enclosure. Worth every knot it may steal. We are headed south and some mornings have been real cold. Once the sun is up I am in tee shirt and shorts while others without enclosures are in winter coats, scarves, hats and gloves; I'm dead serious. They look sooo cold. And, when it blows hard or rains, I'm snug as the proverbial bug in a rug. To my mind, it's "knot" even worth thinking about.
Attached Thumbnails
image.jpg  
hmason is offline   Reply With Quote
Old 11-09-2013, 05:36 PM   #7
Senior Member
 
IntervaleII's Avatar
 
City: Tokyo, Japan / Tampa, Florida / Washington, Virginia
Vessel Name: Mondai Nai
Vessel Model: Nordhaven 55 - 45
Join Date: Mar 2013
Posts: 328
Tides and current will effect you. You would be surprised how it even effects you out in open water. I have a full displacement hull with 8.5 kt hull design. When traveling in the Gulf of Mexico I have experienced at 1-2 kt difference depending on head winds and bow seas. I am also starting to understand the currents out there to help me.

Sent from my iPad using Trawler
IntervaleII is offline   Reply With Quote
Old 11-09-2013, 05:39 PM   #8
Guru
 
psneeld's Avatar
 
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,148
Hot - flybridge under bimini or no bimini (no enclosure)
Cold - lower station with bus/diesel heater on

Comfy from NJ to Florida in December....

best part...no $10,000 worth of canvas and vinyl to worry about or keep clean or struggle with zippers as the warmth of day changes...
psneeld is offline   Reply With Quote
Old 11-09-2013, 05:43 PM   #9
Guru
 
hmason's Avatar
 
City: Stuart FL
Vessel Name: Lucky Lucky
Vessel Model: Pacific Mariner 65
Join Date: Aug 2013
Posts: 2,760
Quote:
Originally Posted by psneeld View Post
Hot - flybridge under bimini or no bimini (no enclosure)
Cold - lower station with bus/diesel heater on

Comfy from NJ to Florida in December....

best part...no $10,000 worth of canvas and vinyl to worry about or keep clean or struggle with zippers as the warmth of day changes...
Hmm, your boat photo sure looks like it has an enclosure.
hmason is offline   Reply With Quote
Old 11-09-2013, 05:46 PM   #10
Guru
 
psneeld's Avatar
 
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,148
Quote:
Originally Posted by hmason View Post
Hmm, your boat photo sure looks like it has an enclosure.
old pic...it was the first thing I trashed...I have also replaces the flybridge privacy curtains with black ABS ...

I HATE canvas....way too expensive, even if you do your own...and I hate worrying about it flapping a bit in a breeze and tearing seams.

Here a month old pic.
Attached Thumbnails
Photo204.jpg  
psneeld is offline   Reply With Quote
Old 11-09-2013, 06:13 PM   #11
Guru
 
hmason's Avatar
 
City: Stuart FL
Vessel Name: Lucky Lucky
Vessel Model: Pacific Mariner 65
Join Date: Aug 2013
Posts: 2,760
Quote:
Originally Posted by psneeld View Post
old pic...it was the first thing I trashed...I have also replaces the flybridge privacy curtains with black ABS ...

I HATE canvas....way too expensive, even if you do your own...and I hate worrying about it flapping a bit in a breeze and tearing seams.

Here a month old pic.
Our enclosure is made of a material called Stamoid. A tad more expensive than Sunbrella but should last way longer. It is a vinyl type material that hoses right off, won't get moldy or deteriorate. It is double stitched with Goretex. The windows are Strataglass Low E that block UV and have a very slight tint. All zippers are heavy duty nylon, also double stitched with Goretex. It is now at the end of its first year and looks like the day it was installed. I hope I can say the same 5-years from now. Our FB is quite large, and surprisingly, the entire job came in under $8K. The FB does not get a drop of water even in a wind driven downpour. It's almost hard for me to believe.

We are liveaboards and the ability to sit and relax on the FB on a chilly or windy day is like having an extra room.

BTW, on our prior boat, a Grand Banks 36 with a bimini only, I hated snapping on the FB cover only to take it off and fold it up the next morning. The windows on the enclosure are a lot easier. Again, different strokes as they say.
hmason is offline   Reply With Quote
Old 11-09-2013, 07:50 PM   #12
Guru
 
psneeld's Avatar
 
City: Ft Pierce
Vessel Name: Sold
Vessel Model: Was an Albin/PSN 40
Join Date: Oct 2011
Posts: 28,148
There's a reason there are so many canvas people out there....wherever I can replace it or avoid it....I will...

having run hundreds of boats, maybe thousands, as a pro skipper...no canvas for me....new materials or not.
psneeld is offline   Reply With Quote
Old 11-09-2013, 07:59 PM   #13
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Vessel Name: Carquinez Coot
Vessel Model: penultimate Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 12,559
Don't need any canvas (unless you count the sails and dinghy cover.)

__________________
Kar-KEEN-ez Koot
markpierce is offline   Reply With Quote
Old 11-09-2013, 11:46 PM   #14
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,569
Quote:
Originally Posted by markpierce View Post
Don't need any canvas (unless you count the sails and dinghy cover.)

Mark - That is obviously your favorite pict!!
Art is offline   Reply With Quote
Old 11-10-2013, 05:06 AM   #15
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
Horsepower / Power in Watts Required to Overcome Air Resistance
The horsepower required to overcome air resistance is the speed in miles per hour, cubed, times the frontal area in square feet divided by 150,000
Where:

MPH = Speed in miles per hour
FA = Frontal area in square feet
HP = Horsepower
150,000 = A conversion constant

And don't forget "tail end" drag ... the suction that creates the station wagon effect.
RickB is offline   Reply With Quote
Old 11-10-2013, 05:24 AM   #16
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 22,553
IN FL the noisemaker is usually on to power the air cond. in the sealed Oxygen tent.

Boating in canned air , a new way to enjoy the day!
FF is offline   Reply With Quote
Old 11-10-2013, 05:29 AM   #17
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
Quote:
Originally Posted by Art View Post
Mark - That is obviously your favorite pict!!
http://epapers.bham.ac.uk/1723/1/2013-03_D_Houghton.pdf
RickB is offline   Reply With Quote
Old 11-10-2013, 05:41 AM   #18
Art
Guru
 
Art's Avatar
 
City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,569
Rick - Interesting, Thanks! - Art

And where does this leave us re Mark's favorite picture?? LOL

An Excerpt from link you provided:

"Within the multi-dimensions of disclosure, it has been argued that there are two distinct properties, or continuums: breadth and depth (Collins & Miller, 1994; Joinson, 2001; Moon, 2000; Spiekermann, Grossklags, & Berendt, 2001; Tidwell & Walther, 2002). Breadth relates to the quantity of information disclosed (both frequency and category), and depth to the quality. Depth can range from surface information, such as demographic data, to more core values, such as sexual fantasies and desires (Altman & Taylor, 1973; Joinson & Paine, 2007). Choosing to disclose different information of varying depth and breadth is based on a number of factors including the environment or situation in which the individual finds themselves and their own personal characteristics."
Art is offline   Reply With Quote
Old 11-10-2013, 06:15 AM   #19
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 22,553
Rick needs to add in all the small stuff , masts , a fence around the deck, dink hanging .
FF is offline   Reply With Quote
Old 11-10-2013, 06:19 AM   #20
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
It's all part of the frontal area. Those who are interested can calculate that area and add it to the total.
RickB is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 02:03 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012