Learned a new one: Derecho

PascalG

PascalG

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https://en.wikipedia.org/wiki/Derecho Don't think I heard the word till today but it turned out it s what hit us last week while anchored near Staniel in the exumas.

We knew there was a front coming thru with forecast varying between 25 and 40kts, out the WNW So we tucked in behind big majors to get some protection.

Around 5pm dark clouds moved in and wind suddenly picked to hurricane force. We don't have an anemometer but a nearby boat reported 70kts when theirs blew. Others recorded between 55 and 80+ , with as much as 100 clocked at WArderick wells (exuma park headquarter) where some morings failed

Our location turned out to be not so protected with the wind quickly shifting north and funneled between the cays.

Spend two hours at the helm assisting the anchor. We dragged about three boat lengths with the initial gust and then appeared to be holding but I wanted to relieve the stress on the ground tackle as well as be ready to dodge some of the boats that were dragging. Altogether not a lot of fun especially in the dark

Others where not so lucky... A few sailboats dragged on the rocks, numerous boats lost their dinghies or their outboards after teh dinghies flipped in the wind, and some lost anchors, chain, etc...

Bottom line, even in paradise, watch the weather and assume the front or squall will be worst than forecast. TS is why I normally don't leave the tender or jet ski in the water at night... One fewer thing to worry about...
 
Where was the associated land based severe thunder-storms. Sounds pretty much like a hurricane. Did you see any satellite images.
 
Real soon? In the Bahamas?

Mark this spot for timing purposes.
 
Sounds like things got pretty dicey there , Pascal, particularly after dark.

Since you mentioned hurricane force winds, it's a bit of a shock to also read about the ~~1 day January Atlantic Hurricane "Alex" at the Azores, now downgraded to tropical strength.
 
--> boatbum

"Real Soon Now", old school hacker speak meaning "This is vaporware, and you grandchildren will die of old age prior to the issue of version 1.0" aka: What marketers would say about patches for serious bugs.

Actually, I have been ( loosely ) following Bahamas politics and while the announcement was likely politispeak, should they find two or three times the money required for such a system, it will likely be implemented only slightly overbudget.

Same for "When will they resume picking up garbage and properly disposing of it from Bimini? answer: Real Soon Now
 
We had a derecho come through one June or July a few years ago. Straight-line winds clocked up to I think 85 mph or so... bunch of boats in our marina lost canvas, the yacht club next door lost a 100' oak tree... power lines down all over the place... etc.

-Chris
 
The remnants of storm moved the NE into the Atlantic and became or were absorbed by Alex

Not holding my breath on bahamas radar. The Bahamas meteorology office page is frequently down and doesn't offer nassau radar images anyway
 
We became familiar with "derecho" in June 2012. We were on the boat at the docks in Chesapeake City, MD on the evening of one of the worst derechos to be recorded. It sank a few boats in the cove, as well as many others down the bay. Many large trees were knocked over. Power was out at my house in VA for several days. The storm caused a couple dozen deaths. https://en.wikipedia.org/wiki/June_2012_North_American_derecho
 
June 29, 2012 was the exact date of the derecho that Glenn mentioned. It was during that night into June 30th. Ripped through the Upper Chesapeake Bay like hurricane. I remember that date because it was our anniversary, our retirement date and the day we moved full-time to our home here. Lost power that night and learned that we'd be without power for several days. Drove to Middletown, DE to buy a generator... Lowes was already sold out and I got the last big one at Home Depot. Hell of an introduction to retirement on the Maryland Eastern Shore!
 
They were about half mile behind us. I initially anchored there earlier in the afternoon but thought it was a bit too exposed and too close to the rocks.

We really felt for all these boats as they had to ride this pretty much exposed to the elements as dodgers and Biminis didn't hold up. We were lucky to be up in an air conditioned and dry fly bridge
 
Pascal, as much as you anchor out and after having two different size claw anchors drag on you in a blow, you might want to consider looking at getting one of the newer style of anchors with track records for better holding ability than a claw. I know they are not cheap but the alternative can be rather expensive as well. Just say'n. :-)

Something to consider for future reference is that when a blow like that is predicted for that area, don't know if that one was, tucking in the cut between Big Majors and Little Majors gives you very good shelter from the winds. The holding there is good too.
 
Well the fist 110lbs was too small for rthe boat. This one (176lbs) is a great anchor and has held us in some normal blows (50 kts) many times. This one was very unusual.

Yes, we were Between the Majors whcih is a sheltered spot when the wind blows from the W or NW in yoru typical frontal passage. In this case the wind was more northerly and funneling between the cays accelerating in a Venturi effect. Been there before, actually last winter we spent two days there during a strong front holding a 74 viking rafted up to us.

The main reason we dropped 200' in the initial gusts is that I had scope for the expected westerlies and the limited width of the anchorage. There was no room for more. By the time the wind had shifted to the NNW adding scope would have gotten us too close to tanother boat and so assisting the anchor with idling engines was a better option which also reduced stress on the ground tackle.

I love my big claw... Not about to change it :)

Btw the other lesson from this is to make sure the end of your chain is secured in your anchor locker with a length of line. It should be long enough to pass thru the windlass so that in an emergency it can be quickly cut loose from the deck. This is always part of my pre departure check list when I get on a new to me boat and I often find the end of the rode loose. An alternative to securing it to the locker if no eye bolt is installed is to tie a large knot at the end so it can't go thru the deck. In this blow two or three boats lost their anchors including a big hatteras MY jsut up the anchorage from us forcing them to motor into the wind the whole time... The got sideways a few time making everyone very nervous.
 
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