Storms: Canvas Removal??

[Phyrcooler]

During my years sailing, there weren't canvas bimini or flybridge enclosures to worry about. Now that I have a powerboat with an enclosed bridge - at what point do you remove it in the face of predicted storms and winds? My canvas and supporting assembly are in good condition and I believe fairly solid, but is there a wind speed threshold where you would say... "I really ought to take that down"?

SoCal isn't exactly hurricane country. But with the predicted "El Nino" weather this winter, we might get some heavy rain storms and accompanying winds. Highest that I have seen data for accompanying past storms were in the 60's to mid 70's. Enough to worry about?

 

[Drake]

I would remove my flybridge enclosure way before 60mph winds. Probably 30mph at most. Bimini is attached more solidly, but I would take it down if I was expecting anything like 60mph.

In all probability, it's coming down one way or the other at that wind speed. The only question is whether or not you'll have the option of putting it back up when the storm is over.

 

[jwnall]

Here in hurricane country, I remove mine if the predictions are for sustained winds of 60 knots or more. An occasional gust (such as in a severe thunderstorm) is hard to predict, but I would rather be safe than sorry in sustained winds.

 

[Rogerh]

I am pretty much the same as jwnall. Stroms come through with 50 to 60 mph winds but they are quick relatively unannounced thunder storms. No chance to pull canvas and if you could you would be doing it often. Sustained on the other hand we know about and take action. Sixty is my limit also.

 

[healhustler]

60 MPH for our veranda canvas, 80 for the skirts on the upper deck.

 

[BruceK]

During our April storms with sustained high winds over 3 days reaching 135kmh, a Riviera sports boat had all its press stud attached covers removed, by the wind. Other boats like ours lost none, ours are on toggle clips. Our bimini survived, as did the others.

 

[ranger58sb]

Our enclosure panels are all Sunbrella, attached to the boat by a combination of beads-in-tracks, #10 YKK zippers, and snaps. All of the YKK "structural" zippers (i.e., not the smiley window coil zippers) are over-covered with a flap that uses hook-and-eye to close over the zippers.


We had a derecho through here a couple years ago, winds guestimated afterwards as about 70 mph (neighbor boats lost canvas, next door yacht club lost a 100' oak tree)...


And our enclosure panels -- which had just been installed a couple days before that -- survived nicely.


That said, when we have a hurricane prediction, anything over about 50 mph sustained winds, and especially if it's really no kidding coming here, the enclosure comes down. I feel I don't need to tempt fate, and that also gives me some additional comfort given wind predictions and eventual reality sometimes don't exactly match.


-Chris

 

[psneeld]

wow you guys are brave.


For new canvas and hardware...60 knots might be a good number...but for anything less than 100%...I personally would back it down towards 35...that gives a cushion if the forecast is light and it gusts higher.


Of course there are different level of canvas construction, materials and supporting structure...I am speaking to the lighter, more common setups.


Any canvas setup like a bridge enclosure with only 3 sides can get destroyed easily by 35 knot winds if any of the corner fasteners fail...have seen plenty self destruct.


Also any canvas that peels a fastener in the corner can be lost or just as bad...flog the gel coat with the end of the fastener AND flail itself to ribbons.


I bag my bimini (without any sides) away in anything over 20 knots sustained all day or when thunderstorms are forecast. Going up there to lower my antennas so it is a routine. Mostly to preserve the life of it as if not being uses and flogging isn't helping it any.

 

[Besslb]

Also important to note, that it's not only the wind that your own bimini/enclosure can sustain, but also the flying obstacles that might rip through your soft goods. Just sayin'.

We also would remove our dinghy and sundeck furniture for expected high winds.

 

[TDunn]

I am surprised that every seems to only be concerned with damage to the canvas. Personally I remove all canvass if winds over 50 knots are predicted. The main reason I do it is to reduce the windage of the boat. Saving the canvas is secondary. Note that I am talking about my sailboat since the only canvas on my powerboat is a cover on the butterfly hatch. That stays on for any storm since it keeps the hatch from leaking.

 

[Phyrcooler]

I am surprised that every seems to only be concerned with damage to the canvas. Personally I remove all canvass if winds over 50 knots are predicted. The main reason I do it is to reduce the windage of the boat. Saving the canvas is secondary... snipped

Good point on windage. I've felt pretty comfortable in my slip with 6 points tied down. But did go through a pretty windy, wet storm in Ventura last year, and felt a lot of movement, and saw some loosely tied boats really sailing around their slip.

 

[Rogerh]

Agree on the windage being a big concern. On any tropical storm that may develop or already has it comes off. We have a pretty stout arrangement as far as structure. Now as far as thunderstorms in this time of the year we always have significant thunderstorms within 30 miles of us. I would say at least 75 % of the days. They pop up but they are intense and have 50 to 60 mph winds. Mid July throughout August. So we would need to leave it off all the time. When we had the canvas installed he told us that it was good up to 60 sustained. So far that has worked well. We have had some sustained winds in that area. I know that it can happen and now that I talk about it I probably have put a bullseye on us. Any older canvas I would be take down much sooner.

 

[jwnall]

I am surprised that every seems to only be concerned with damage to the canvas. Personally I remove all canvass if winds over 50 knots are predicted. The main reason I do it is to reduce the windage of the boat. Saving the canvas is secondary. Note that I am talking about my sailboat since the only canvas on my powerboat is a cover on the butterfly hatch. That stays on for any storm since it keeps the hatch from leaking.

When I had the sailboat, then I removed canvas at a much lower wind prediction. Partially because it was easy to remove. The trawler is more of a headache to remove, though. I might add (which I forgot when I posted before) that even at predicted sustained winds of 40 knots or so (tropical storm speed) I'll do a wrap of the canvas on the bridge. That is, run a line around it a few times just to try and keep it from flapping in case something does come loose.

All that said, however, if one is going to err, then one should err on the side of caution. Especially with older canvas, as someone has already pointed out.

 

[healhustler]

My canvas is some heavy build and I haven't sustained any damage, but I remove it principally for the reduced windage.

 

[psneeld]

sometimes where you boat is and the winds it is feeling can be quite different than what the forecast winds are...some places higher...many placed much lower.

 

[Phyrcooler]

Thanks all. Good comments and advice. I do like the idea of wrapping a line around to minimize flapping if something comes loose. Might prevent something from getting out of hand. Or not. But probably worth the effort.

 

[Baker]

It is not necessarily the wind speed....but it is the duration that causes the damage. If a thunderstorm blows through with 50-70mph winds very briefly, most installations would not be damaged. But if you have that amount of wind for hours, then that is more of a concern. You get that kind of duration in a tropical storm. So if there is a tropical storm headed for us with over 50mph winds, I would take the canvas off.

 

[ddalme]

Heck, I'm in hurricane alley in So. La. If a 'cane is in the gulf I remove my canvas, dingy and boat.

 

[alormaria]

You are a sailor so you should understand this.
It's the same decision making process as when to reef a sail; You do it when the thought occurs to you.