Bimini Wind Effect

RoyS

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Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Having a bimini installed on my 1980 H33. Bimini is 80" long, tapered to match the boat width, and entirely aft of the boom. I have never had one on any sailboat. While I am looking forward to the shade, I do have one concern. When motoring about the marina, I expect and use the wind which tends to take my bow downwind if I stop moving. Should I expect a different wind effect with a bimini?
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
I've not noticed any significant effect with a Bimini either. Since the Bimini is mostly horizontal, the windage is minimal. However, if you have a full enclosure and the side panels are lowered, then it may be a different story as there will be increased windage.
 
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Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
If there is wind flow thru, you will have more a lift effect, so secure your Bimini down well..............
Good call............I agree, theoretically a little more lift but never noticed that due to the boat's relatively displacement even under a range of wind conditions.
 
Jul 7, 2004
8,402
Hunter 30T Cheney, KS
We just had a cover made for our bimini last Fall. When retracted there's a lot of "sail" area still. I don't think it affects us coming into the slip but I have to think it would add drag sailing upwind. Fortunately it's usually open to protect us from the sun.
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
We just had a cover made for our bimini last Fall. When retracted there's a lot of "sail" area still. I don't think it affects us coming into the slip but I have to think it would add drag sailing upwind. Fortunately it's usually open to protect us from the sun.
Anything that sticks up above the deck will add windage, even the mast and stays. If we were into elite racing for big bucks then all of us would obsess about windage. For most of us, it is a trivial loss in speed.

But that is why it is called a Dodger. Dodging wind, rain, and bow waves splashing.
Jim...
Yep, mostly I sail with the center panel rolled up and the side panels stored below. When it is nasty out then the side panels are deployed, the connecter is installed and the center panel rolled down.
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
Yep, mostly I sail with the center panel rolled up and the side panels stored below.
Same here, but I stripped them all off for Hurricane Zeta. To much windage then.:facepalm:

Now stored in my home Garage, safe and sound.

We did get caught in a summer Squall, and the Dodger did keep all, but the Captain, Dry.:huh:

The rain was almost horizontal , like throwing Buckets of water in my face.

I now have a dive mask stored aboard so the Captain can see.:thumbup:

Captain Jim...
 
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capta

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Jun 4, 2009
4,766
Pearson 530 Admiralty Bay, Bequia SVG
We are a big, heavy boat, but since I've not sailed a single day without my bimini up, I can't say for certain. A well made bimini should be tight as a drum, IMO, and therefore not much of a wind catcher. I just plain would never sail without a dodger and bimini again.
On smaller boats I've sailed, the bimini didn't seem to be much of a problem.
 
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Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
I have a much smaller boat and I still don't really notice much windage on my bimi. I suspect you won't notice it either on your larger boat.
 
Jul 12, 2011
1,165
Leopard 40 Jupiter, Florida
You won't even notice it, @RoyS . I've been at slow speed with the bimini up and down on our C36, and the bow still falls off before the stern in a cross-wind. We take it down for the occasional club race, but I think more for form than for practical sail effectiveness.
 

RoyS

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Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Thank you all for your inputs. You have answered my question. The dog and I are excited about the shade. My poor wife will have to move about to stay in the shade as she will be mostly forward of the new bimini in the cockpit. Get her a big hat, maybe.
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
.........................The dog and I are excited about the shade. My poor wife will have to move about to stay in the shade as she will be mostly forward of the new bimini in the cockpit. Get her a big hat, maybe......
You can have the bimini designed to cover the entire cockpit so you, dog AND your wife can be covered. Do internet search on "Hunter 33 Bimini Images" and you will find lots of examples.

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Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
A caution about large biminis. Think about cockpit access with a large full Bimini. When the Bimini extends to front of the cockpit, it becomes more difficult to enter and leave the cockpit, which if you are short and young is not much of an issue, but if you are old and tall, the bending, twisting and stooping to get under the Bimini is not much fun.

A good alternative is a dodger and Bimini combination with a connector piece between the two. The connector piece is used only when addition protection from the weather is needed, sun or rain, the rest of the time it stays neatly stored. When removed there is about a 2' space between the dodger and Bimini which allows much easier access. Your back and knees will appreciate it.