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Old 11-09-2013, 12:42 PM   #1
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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.
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Old 11-09-2013, 01:34 PM   #2
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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.
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Old 11-09-2013, 01:42 PM   #3
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Quote:
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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.
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Old 11-09-2013, 01:54 PM   #4
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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.

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Old 11-09-2013, 02:00 PM   #5
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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..
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Old 11-09-2013, 05:07 PM   #6
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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.
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Old 11-09-2013, 06:36 PM   #7
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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.

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Old 11-09-2013, 06:39 PM   #8
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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...
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Old 11-09-2013, 06:43 PM   #9
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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.
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Old 11-09-2013, 06:46 PM   #10
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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.
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Old 11-09-2013, 07:13 PM   #11
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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.
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Old 11-09-2013, 08:50 PM   #12
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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.
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Old 11-09-2013, 08:59 PM   #13
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Don't need any canvas (unless you count the sails and dinghy cover.)

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Old 11-10-2013, 12:46 AM   #14
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Don't need any canvas (unless you count the sails and dinghy cover.)

Mark - That is obviously your favorite pict!!
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Old 11-10-2013, 06:06 AM   #15
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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.
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Old 11-10-2013, 06:24 AM   #16
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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!
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Old 11-10-2013, 06:29 AM   #17
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Mark - That is obviously your favorite pict!!
http://epapers.bham.ac.uk/1723/1/2013-03_D_Houghton.pdf
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Old 11-10-2013, 06:41 AM   #18
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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."
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Old 11-10-2013, 07:15 AM   #19
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Rick needs to add in all the small stuff , masts , a fence around the deck, dink hanging .
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Old 11-10-2013, 07:19 AM   #20
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It's all part of the frontal area. Those who are interested can calculate that area and add it to the total.
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