Scoot strategy

[Godot]

I'm not talking how to "win" the Scoot, as the term doesn't really have much relevance.  Nope, I'm talking about the best way to actually safely and comfortably survive the Scoot.

The big issue ... (insert dramatic music here) the evil, menacing, dangerous, vicious, contrary, annoying, and challenging GULF STREAM! :o

My basic strategy is to leave Beaufort on a breeze with a decided southerly component, sail east to get across the stream as soon as possible, and once across to head as near as I can to our destination.  Simple.

A possible alternate strategy (actual strategy to be determined at the start based on the most recent forecast) is to cross the stream and keep going, I don't know, maybe a quarter or half way to Bermuda before turning south to hopefully have a more comfortable point of sail.

As I recall the pilot charts, I believe most of this trip will be against the prevailing breeze.  Dealing with that head wind will be an interesting component to the challenge (of course, this means the return trip is likely to be much easier).

Just early thoughts ... still got a couple years to figure it all out.

[Captain Smollett]

The destination ya'll picked puts "Route 65" out of the running.  Folks that head to the VI typically go east to the 65'th Meridian then due south. That gets them across the stream, and the navigation is generally straightforward.  Get enough help from the trades and that S course is a broad reach.

This route from Beaufort to either of your destinations lies a little more along the stream axis - closer anyway, with a good chance the wind will be in our teeth.  (yes, I said "our").

To my mind, that makes this a VERY interesting "challenge."  Aside from the length of the run, this is not just a day-romp on some big water.  There is a very real navigational challenge present; I'm thinking about the old days, The Great Age of Sail, and how they would deal with currents like the Stream.

I'll reiterate my earlier comments about boat speed irrelevancy.  The quickest passages will be made not by favored LWL, or even perhaps by shortest distance sailed, but rather by best routing by playing the stream against whatever wind happens to be present at the time.

This is looking to be a VERY interesting event from a sailing "challenge" point of view.  Grog to both of you!

[CapnK]

Seems there could be 2 types of strategy that Scooters might oughta be thinking about:

1) an overall best-projected route based on prevailing winds, currents, frequency of gales, etc...

and

2) what would be the permutations of the above given different factors along what becomes your planned route. For instance: if the wind is steadily more southerly than anticipated and you have to pick one tack over another to grab a few hours of rest or just an easy point of sail, is port tack in Some Area favored over starboard, thanks to a consistent eddy/current known/likely? Or if you are nearly south enough to turn west and make a run in to the destination, but a cold front is forecast to pass through, whats likely the best thing to do, direction to head, are there possible landward-setting currents, or vice versa on your route, where you are?

Yep, lots o' stuff to consider. Good thing that there is like 2 years... Hey - did somebody already say that? ;D

I do know that there was a guy with a Southern Cross 28 based out of Charleston several years back who for at least 2 years sailed Chas --> Bahamas, West End if I remember right. He went in the winter, it seems, and that route is a lot different than Beaufort --> San Salv/Eleuthera. Other than that, I haven't really heard of anyone joining these points under sail or power, though I am sure that people have.

[Captain Smollett]

How far in advance are the Gulf Stream predictions and still be reasonably accurate?

[CapnK]

Well, it flows in a generally SW to NE direction, and has for a while, so I think it's safe to assume it will continue to do so, unless that whole 'melting polar region' thing makes it stop or whatever, in which case we won't be so worried about it anymore, but... ;D

What do you mean as far as predictions? The Stream meanders back and forth a bit, puts out eddies and backflows... It's a current running through a body of water, so there is a lot of variability, obviously... Basically, you can think of it being X miles wide at B-fort, and directly affecting an additional X miles of sea on either side possibly, but until the time comes I don't think there is any way to say "There's an eddy here, and a bend in the Stream over here..." There are several good sites for fisherman/researchers/whatever which show in great detail (if cloud cover hasn't been too thick) the current state of the Stream and associated features, so prolly the best thing to do will be to watch that for a few days prior in order to extrapolate what MAY happen over the few following days when you will be having to deal with it.

Do dat makes sense?

[Captain Smollett]

What do you mean as far as predictions? The Stream meanders back and forth a bit, puts out eddies and backflows... It's a current running through a body of water, so there is a lot of variability, obviously... Basically, you can think of it being X miles wide at B-fort, and directly affecting an additional X miles of sea on either side possibly, but until the time comes I don't think there is any way to say "There's an eddy here, and a bend in the Stream over here..." There are several good sites for fisherman/researchers/whatever which show in great detail (if cloud cover hasn't been too thick) the current state of the Stream and associated features, so prolly the best thing to do will be to watch that for a few days prior in order to extrapolate what MAY happen over the few following days when you will be having to deal with it.

Do dat makes sense?

Right.  That's what I mean.  The guys that run the Bermuda races pay some pretty big bucks to get model predictions of just how the flow is set up at any given time/where it "will" be during the run.   There are actually private stream forecasters who make their data/forecasts available (for a fee) - of interest to ANYONE plying the waters along the East Coast, not just racers.

(Check out Nick's track, for example...when he was becalmed, it sure seems like he was in an eddy).

How those racers run the eddies plays a MUCH bigger role on passage time than (wait for it...) intrinsic boat speed.  It's been written that the most important crew member for running these events is the navigator, at least if he is doing active routing.

The routing is a very complex optimization problem.  You've got your base polar data for the boat (measured in trials, not design predictions), wind conditions, sea conditions and of course, the Stream and it's eddies.  Some of the eddies can be very small and short lived; the main current is of course more or less a steady state, but the secondary flows are turbulent and thus very dynamic.  The dynamic currents and changes in wind mean the "optimal" routing changes DURING a race, even one lasting only 5-6 days.

The Scoot and these races are of similar duration.  If anything, the Scoot will endure a larger effect from the Stream and it's secondary flows because the route is along the axis rather than perpendicular through it.

Now, is this overthinking the problem in regards to the premise and philosophy of the Scoot? 

Of course.  But for me personally, it's one of the most fascinating and interesting aspects of the Bermuda races.  I've always wanted to participate in one of those races as navigator to 'try my hand' at solving this routing problem.  To me, with my mathematical bent, it just makes it more "fun," if I was going to "Race" at all, than just pointing the boat along a rhumb line and going with the flow (hehe, or against it, as the case may be).  But if I Scoot, the latter is probably closer to what I'll do.

My point in bringing up the predictions was to wonder out loud: "Does it do any good to try to get to detail-ey in terms of routing at this stage, 2 years out?"

I'm just curious if anyone knows the timescale of the forecasts.  Best I can tell from a quick Google search yesterday is that they push them out to about 7 days.

[CapnK]

Seems to me that a better route would be to, once turned to cross the Stream, go SE, crossing as perpendicular as possible, and get to the other side asap into an area where current has a lot less potential effect...

I don't understand why you think you will be traveling along the GS axis...? Unless to get east before turning south, that 'Rt 65' you refer to? Cornells routing (right?) is for the VI as a destination - we are headed much west of that (+/- 10 degrees long.), and at a different time of year than what he recommends as well (according to what someone has posted here, haven't read it myself...), so perhaps not really applicable...

See the following link, 5 years of Stream:

http://rads.tudelft.nl/gulfstream/gif/anim_7_long.gif

(Warning: Animated GIF, 18 mb in size)

In the area of Beaufort, the Stream width is fairly consistent over time (years). Looks like what happens on the other side of it would be as important to consider. Watch the area just east of Bfort and offshore of Hatteras - a very regular strong countercurrent and/or eddy there (and a very nasty reputation)...

Heading S/SSW from Bfort out to the Stream and nick across might get you a boost southwards if you happen to catch on of those regular-looking big eddies just right... But that said, watch the dates, the biggest eddies are *not* there in the April/May time period. Other side of the Stream from Bfort that time of year shows little currents in this animation.

OTOH, the pilots would seem to indicate a pretty straightforward SE to the Trades, then S and W routing...

(Grog to Dave on Auspicious for that link... :) )

[AdriftAtSea]

I think the Scoot will also be affected to a greater degree due to the slower average speed of the boats.  The boats doing a Marion-Bermuda or Newport-Bermuda race are usually a good deal bigger and faster, and as such will cross the Gulf Stream more quickly than the average Sailfar.net type boat.

[Captain Smollett]

I'm kinda sorry I ever brought this up.  It was not intended to start a "debate" but rather was just some thinking-out-loud type musing.

I don't understand why you think you will be traveling along the GS axis...?

Because to set up my dichotomy of extremes, I was contrasting a "fully managed" route against a simple rhumb line course.  Reality is, of course, somewhere on the continuum that connects them.

(For the record, no one here except me has even proffered the notion of sailing Beaufort to S Salv/El via rhumb line).

I don't understand why you think you will be traveling along the GS axis...?

Because the rhumb line course, which I set up as an straw man to be knocked down, does lie MUCH more parallel to the axis than a perpendicular crossing, either to Bermuda or any of your suggestions for getting South (ie, go South, East, South in a dog-leg).

Cornells routing (right?) is for the VI as a destination - we are headed much west of that (+/- 10 degrees long.),

Yes, as I stated when I mentioned it...not a good route for THIS destination.   ;)

n the area of Beaufort, the Stream width is fairly consistent over time (years). Looks like what happens on the other side of it would be as important to consider.

Yep...my 'comments' were geared toward the eddies and 'external' effects more than the stream itself.   We say the stream is "xx" miles wide and that does not change much, but ALL I was trying to say was that the secondary flows are MUCH more dynamic, with many length scales and lifetimes.  Some eddies appear and disappear in a matter of days.

It REALLY doesn't matter.  It's just something *I* am interested in, from both a scientific standpoint (ie, academically) and as the practical matter of how SOME other boaters apply it to the optimal routing problem.

As I said, I'm sorry I brought it up.  I should, by now, recognize that my "interests" are largely irrelevant and not that interesting to anyone else.

But that said, watch the dates, the biggest eddies are *not* there in the April/May time period.

Good stuff.  At least part of my original question is answered, then.  Still leaves short timescale, highspeed (high turbulent kinetic energy dissipation) eddies as a "concern," but again, perhaps only as an academic concern.

I'll stop now...and I'll try to remember the next time anything having to do with "flow" comes up to just keep my "musing thoughts" to myself.

[CharlieJ]

No - Please keep kicking out the thoughts. I was interested, if no one else was.

[Godot]

My point in bringing up the predictions was to wonder out loud: "Does it do any good to try to get to detail-ey in terms of routing at this stage, 2 years out?"

In answer to this one question:  No, it doesn't do much good to be specific about a route two years in the future.  It DOES have interest, though, in understanding what the issues are that need to be considered.  I don't know all that much about the habits of the Gulf Stream.  I'm just starting my education.  Specifics come later.

[Auspicious]

If you have the time and interest, I think there is great value in saying "I'm leaving in two days -- what would I do" and looking at all the current weather products. You can even estimate your progress against actual conditions. This gives you the chance to learn from experience without being pounded by conditions. <grin>

[newt]

I second the discussion captain. I find what ifs very interesting and important for the preparation of any navigation. A what if that we are not addressing is what if we get out in the gulf stream and get becalmed. Are we all going to Ireland together? The point is it may make sense to have to cross the stream at its narrowest- just out of Miami, instead of a couple of hundred miles into the Atlantic. I mean sure it is out of the way, pain in the arse- but it might be safer for small boats. (notice- I say might be)
Then we could sail to various way points and let everyone else get caught up.  Just a thought.

[CapnK]

Just talking and asking questions, John. Enjoying the discourse. No need to stop posting yours! :) There's lots of time ahead to do so, and it's never to early to start asking questions and posing "what if's", IMO...

Good suggestion for an exercise, Dave. I like that idea a lot... and will likely start doing it.

Newt - going from down there, with multiple waypoints as destinations/gather spots - sounds kind of like it could be done like the old-school car rallies. An inter-Bahamas Rally. :) A 'ScootSouth' that does that, could happen nearly the same time as the Scoots leaving Beaufort, and the two Scoots could meet up in the Bahamas. Now *that* would be awesome... ;D A ScootGulf could come around... The possibilities of Scoot are endless. :D

Grogs! :)

[Captain Smollett]

Okay, I'll jump back in.

Looking at that VERY COOL animated gif Kurt posted above, there actually are some rather large, reasonably intense short lived eddies cropping up in the vicinity of the Grand Bahama and Great Abaco...bringing with them their associated positive currents (heading a southbound vessel) and countercurrents (providing a lift) depending upon how you hit the eddy.

I'm wondering, spitballing here, if Rock Sound on Eleuthera is the destination (or that Yacht Club nearby), would a "Route 76" be a good strategy?  Sail ESE or SE from Beaufort (if the breeze on at the start allows this course) until hitting the 76th meridian, then due S to the tip of the island, turn to stbd and you're home.

This route avoids most of the eddies except when right in tight with the stream itself.  Playing the eddies can help or hurt depending on which side you hit 'em.  Avoidance is the conservative approach...low "risk" but low chance of a favorable current.

Finally, this route avoids the need to navigate through the islands NW of Eleuthera, or pass well to the W of the Bahamas (and be in the Stream's area of influence in the Straits).

Thoughts?  Opinions?  JR is CRAZY comments?

Edit: I posted some images from 30 April for past six years in my gallery.  Lots of year-to-year variation in the area of Grand Bahama...some years, a 1 knot boost, others, a 1 kt drag.

[Pappy Jack]

Glad to have you back in :). I ,for one,need all the help I can get ::).

Fair winds and full sails,

Pappy Jack

[Amgine]

Since it's just a mental exercise for me, being on the left coast, I figure'd I'd revive this one for a moment.

In looking over a couple of histories of the GS, it looks like there's a steady SSW eddy paralleling the shoreline from Beaufort, down to about Georgetown, SC. And there's often a narrowing of the GS off Georgetown/Charleston.

The winds might not be favourable (I dunno, and not finding climatological wind info very easily atm), so it may be a very dumb idea to follow the coast for 125 miles before cutting across the stream. But what would local sailors who've done this sort of thing have to say?

[CapnK]

Amgine - I've thought about that too, because there is a regular counter current running down the coast towards Cape Fear. I don't know if it is strong/swift enough, or if it offers that much of a shorter crossing, to make using it that way worthwhile, but have not yet ruled it out.

I don't think coming as far south as G-town and Chas would be worthwhile though, unless it was purely in order to make a GS crossing as short as possible and you *knew* that the GS was much thinner there... Cape Fear is more of a possibility, in that the shoals there might allow one to 'sneak out' to the deeper water near the GS without being side-set by a southerly current. This is conjecture, though, and my experience in the area leads me to believe that that is all it will ever amount to. :) The currents here just aren't strong enough to make that much of a detour worth it, I don't think.

I'll have an eyeball close on the weather and currents throughout April and May this year, to watch what happens. :)

Looks like you are doing some planning of your own out there. :) Kewl!

[Auspicious]

I read this a few years ago but just stumbled across it again. An interesting story and a clear indication that Mother Nature doesn't care so much about out plans.

[Captain Smollett]

I read this a few years ago but just stumbled across it again. An interesting story and a clear indication that Mother Nature doesn't care so much about out plans.

That was November...a different weather pattern (and storm probability) than April/May. 

Ever the optimist.... :P