Australian Golden Globe Race entrant - yacht lost

[Wing Mark]

I should like to see you explain to me how a Rustler 36, with a reverse raked stern and outboard rudder, increases her dynamic DWL when heeled.
She is not an IOR design either, for that matter.
I too think that, as racing boats, contemporary shapes are much superior to those built under IOR rule.
The extreme interpretation of the IOR rule essentially led to what amounted to a double ender with extremely steep buttock lines that had a tendency to suck up the stern wave, effectively preventing above displacement speeds. To provide stability to these very light boats, beam was added amidships. As speed increases, the developing amidships wave through would severely diminish such stability, which in turn promoted the famous death roll behavior when running hard under spinnaker.
As usual, racing success also bred a whole slew of cruising boats, including motorsailer/deckhouse designs, that mimicked typical IOR features.

In regards as to hull shapes, apart from foiling designs and even that is highly debatable, there is not much new under the sun and much of what is now heralded as cutting edge contemporary can be found in Great Lakes scows, 19 century sand baggers or skimming dishes, including twin rudders, asymmetric twin dagger boards, wide sterns, etc.
The biggest and most significant progress has been made in the application of new materials that now allow us to save (significant) weight while assuring such shapes stay stuck together, mostly anyway.

If you fancy to sail a boat with minimum rule restraints, get a Moth dinghy. Let us know how your cruising goes.

There is a strong tendency on this forum to compare apples and oranges. When someone points out that a 30' overall cruising boat with basic modcoms, as we have now come to expect, the power generating and storing infrastructure to support this, an engine to reach hull speed in full trim and adverse conditions, proper ground tackle to stay in place once you arrive and a set of bicycles for shore excursions, is not likely to plane, then some wag will post a pic of a 60' carbon sled that features a washer/dryer to prove that contemporary design is not only better, but faster.

The Moth is actually a very good example of fixating on e arbitrary constraint, length as measured in a particular way.
Before they went foiling. the notional 'hull length' became a joke, as the real length was increased by a rudder gantry.
Now they have a prodder sticking out the front to hang the wand, or ride height sensor, from.
It's notionally an 11ft boat, but you could build a better boat for the same money if you dumped the 11ft restraint not including this and that.

Likewise various skiffs are longer than their headline 'length' with rudder gantries at the blunt end and bowsprit brackets at the sharp end. You won't get a '16ft' skiff in a 17ft shed.

Rustler's design was probably constrained by what they thought their buyers wanted the boat to look like.
If people wanted the fastest boat for 36' on deck, then they'd have a plumb bow and transom.

 

[roblpm]

Some heresy here. Maybe AWBs are safer after all?

What can be learned from the 2018-19 Golden Globe Race?

"The cruiser’s angle of vanishing stability will likely be at a far lower angle. “People might point to that and say the old boat is much more stable, it doesn’t have a vanishing angle until, say, 145°, so it’s a much safer boat.

“However, with a larger and/or modern yacht, especially with a deep keel and bulb, if you look at the righting moment – the top peak of the curve – it is likely to be quite a lot higher and the area underneath that curve is greater.

“It’s that area under the curve that is of most importance, because it’s directly equivalent to the energy required by a wave to roll the boat. The greater the area, the less likely to be rolled in the first place,” he explains.“

 

[Laminar Flow]

Some heresy here. Maybe AWBs are safer after all?

What can be learned from the 2018-19 Golden Globe Race?

"The cruiser’s angle of vanishing stability will likely be at a far lower angle. “People might point to that and say the old boat is much more stable, it doesn’t have a vanishing angle until, say, 145°, so it’s a much safer boat.

“However, with a larger and/or modern yacht, especially with a deep keel and bulb, if you look at the righting moment – the top peak of the curve – it is likely to be quite a lot higher and the area underneath that curve is greater.

“It’s that area under the curve that is of most importance, because it’s directly equivalent to the energy required by a wave to roll the boat. The greater the area, the less likely to be rolled in the first place,” he explains.“

I think the issue is a lot more complex than simply comparing (hydro)static stability curves ...

 

[Laminar Flow]

The Moth is actually a very good example of fixating on e arbitrary constraint, length as measured in a particular way.
Before they went foiling. the notional 'hull length' became a joke, as the real length was increased by a rudder gantry.
Now they have a prodder sticking out the front to hang the wand, or ride height sensor, from.
It's notionally an 11ft boat, but you could build a better boat for the same money if you dumped the 11ft restraint not including this and that.

Likewise various skiffs are longer than their headline 'length' with rudder gantries at the blunt end and bowsprit brackets at the sharp end. You won't get a '16ft' skiff in a 17ft shed.

Rustler's design was probably constrained by what they thought their buyers wanted the boat to look like.
If people wanted the fastest boat for 36' on deck, then they'd have a plumb bow and transom.

None of what you say makes the Rustler's WL any longer.

 

[capnsensible]

Coming Soon! The Golden Globe Race!!

Watch enthralled as Armchair Sailing meets The Mighty Oceans!

 

[Kukri]

Coming Soon! The Golden Globe Race!!

Watch enthralled as Armchair Sailing meets The Mighty Oceans!

Because whilst I am never going to own an IMOCA I might very well own a Rustler 36, a Tradewind, an Endurance, a Nic 32, etc. And that’s the special attraction of this race.

 

[Stemar]

There should be a cost adjusted result as well as the handicap results!

If the other halves of sailors in general, but racers in particular, ever find out the true cost, there'll be a significant reduction in the number of particpants ?

 

[flaming]

Well the Najad is now doing 5.2kts and the Pogo 5.6kts. is it really worth all that discomfort for 0.4kt? I don't think so. They are 4nm miles apart after 500nm. What the point of a Pogo on an Ocean passage?
Just remember that the boring lead keel, centre cockpit boat with Spade rudder, full teak interior weighting 18t light is ahead of many larger well respected boats such as an Oyster 72, Ben 58, X Yacht 50 and numerous cruising cats. It's not a proper race but I bet the Pogo crew are trying hard. Can you imagine the humiliation if a centre cockpit cruiser with kids on board beat them to the line?

Well the Pogo is now nearly 50 miles ahead of the Najad and looks like it will be 4th monohull home, with the 3 ahead of them at least 12 foot longer. That Oyster 72 must have been reading this thread, they really put the hammer down after we mentioned they seemed a bit slow....! Looks like the pogo made a slight routing error in the middle part of the race and pushed too far east, but since we first mentioned them they've been significantly faster than the boats around them, and extended on everything except boats that are significantly bigger.

But yeah, really slow these Pogos...

 

[flaming]

Actually the Najad is only 2' longer on the DWL this would, theoretically, give her an advantage of 1.3%. This is countered by the fact that the Najad's nominal (empty?) displacement, sources vary, is between 17.5 t and 18t. The Pogo's displacement, if the sources are to believed is 5.5t empty (I mean really empty) and 7.5t in full cruising trim (this is with full tanks + crew with minimal effects and which alone take up half of the proposed load.

A similar line of thought was followed a while back when we were all encouraged to join the collective enthusiasm as a Pogo 12.50 managed to cross the Atlantic at an average speed of 7.5 kts. Well that equates to a relative speed of 1.1 based on her length of DWL. To be sure, I can cite several instances where this relative speed was considerably exceeded by bog-standard sailing craft including some with long keels.
I have no doubt that Pogos et all can greatly exceed the speeds of displacement craft, but, just as reaching or exceeding (nominal) hull speed for non-planing types requires a specific weather and wind window, so do planing types require the right conditions as well. Until the planing model can actually take off, both types are functioning within the same parametres, provided there is a fair parity in SA/D ratio.
In this context it should be noted that for each additional 500lbs (227kg) of load, one requires 1 additional HP to reach hull speed. In terms of a F4, a common wind strength on a East/West passage, the boat would require an additional 50sqft per 500lbs to reach hull speed.
Ironically, the Pogo's published speed predictions are based on the empty boat weight and without even a crew onboard. To reach her projected speeds, she would need an extra 440sqft of sail when fully loaded. While she may well still be able to reach critical velocity, even with this additional load and given sufficient wind, it will narrow her performance window considerably and may very well make an exceptionally fast passage impossible.

The latest Pogo to launch, the 44, when loaded with full tanks and 2 tonnes of gear has a D/L ratio higher than a Melges 24 with it's crew onboard.
Pogo 44 boat test: designed to thrill - Yachting World

You keep talking about "published speed predictions." Where are these published please? I've never seen them.

 

[flaming]

None of what you say makes the Rustler's WL any longer.

But that's the point... comparing boats that have the same LWL is a bit pointless, because boats are not designed in the same way any more. You wind up comparing 36 foot LOA old boats with 28 foot new boats. Most people, when buying a boat, aren't looking for LWL, they're looking at LOA, to determine how much space they have inside, or how much they have to pay to berth it.

 

[Mark-1]

Well the Pogo is now nearly 50 miles ahead of the Najad and looks like it will be 4th monohull home, with the 3 ahead of them at least 12 foot longer. That Oyster 72 must have been reading this thread, they really put the hammer down after we mentioned they seemed a bit slow....! Looks like the pogo made a slight routing error in the middle part of the race and pushed too far east, but since we first mentioned them they've been significantly faster than the boats around them, and extended on everything except boats that are significantly bigger.

But yeah, really slow these Pogos...

Plus - if the theory is the Pogo was slow because it was more sensitive to weight - it should be getting lighter and lighter as the race progresses.

 

[dunedin]

The speeds of a single boat in something like the ARC don’t give much indication of true performance, for a number of reasons:

• It isn’t a race, so different skippers / crews take different approaches - some fast boats, possibly with young children on board, sail most of the way reefed down, most who are not in a hurry drop kites and possibly add a reef overnight. Other boats, not necessarily fast by nature, are fully crewed with ex dinghy racers and hoist the kite at the Canaries and leave up till the harbour entrance (or possibly on the 2nd or 3rd kite if blown out in a tropical squal.
• Some are paying for weather routing every 12 or 24 hours, from people like Chris Tibbs. This can make a huge difference in keeping in the right wind speeds and avoiding the holes and headwinds.
• A dead downwind route is not ideal for modern asymmetric kite boats, who need to do a lot more distance, whereas most older boats can trundle on at hull speed dead downwind, almost irrespective of sail set.
• etc

I did the ARC on a 45 foot fast cruiser which never hoisted a spinnaker, but went almost the whole way goosewinged with large genoa up, day and night, and was well balanced so generally kept full sail safely through the squalls - and weather routed the whole way. A 40 foot Pogo finished just behind us, but had not been taking weather routing and had covered 1,000 more miles - and blown out their main kite.
The Westerly, Moody, Najad, Malos etc were days behind - but were happy with their trip. Meanwhile we couldn’t quite keep up with a 60 foot classic yawl, sailed like a Volvo Ocean Racer the whole way which “won” overall on handicap.

The “handicap” figures used by ARC are rather more realistic indications - as they represent accumulated experience of 200+ boats sailing this route over 25 years.

 

[Laminar Flow]

But that's the point... comparing boats that have the same LWL is a bit pointless, because boats are not designed in the same way any more. You wind up comparing 36 foot LOA old boats with 28 foot new boats. Most people, when buying a boat, aren't looking for LWL, they're looking at LOA, to determine how much space they have inside, or how much they have to

The latest Pogo to launch, the 44, when loaded with full tanks and 2 tonnes of gear has a D/L ratio higher than a Melges 24 with it's crew onboard.
Pogo 44 boat test: designed to thrill - Yachting World

You keep talking about "published speed predictions." Where are these published please? I've never seen them.

pay to berth it.

Until a boat starts to plane, if it is at all able to, WL is very much the point in terms of performance.
DWL is a key factor for any number of performance related ratios.

Market restraints (popular choice, economics of moorage) are hardly indicative of good performance: if MoBos where long and narrow, they would be faster, much more economical to run and more seaworthy. Instead they are short and fat and three stories high, as are some sailing cats, for example.

If I recall correctly, the VP for the Pogo 12.50 was on the French Pogo site, there are plenty others to choose from. Applied weight for calculations was the empty weight of the boat (in small print at bottom of the page). Same for the new Halberg 40: also empty "standard" boat. Also, often the sails carried on various courses are not indicated.
Given that above a relative speed of 1.1 ( there's that pesky WL, again) even the slightest increase in weight has a significant impact on speed, and on that basis alone one could call such calculations BS. The much applauded passage of a 12.5 Pogo at an average speed of 7.5kts equates to a relative speed of ( surprisingly)1.1 - one does have to wonder.

Re Pogo 44: It's back to the apples and oranges. The 60' carbon sled with the washer/dryer surely has to be next. The simplest way, and in every sense, to lower D/L is to increase the length of WL.
2t of load on a 44' WL has a lot less impact than packing the same load onto 27', which is where this discussion began and why sailors have come up with so many and sometimes bizarrely interpreted rating rules.

The fixation on absolute speed, rather than the more equitable and, unless a boat can actually plane in reasonable conditions, relative speed, led to such, by today's standards, ridiculous situation that victory is granted to a 170t schooner America over a much smaller 48t Aurora, even though the latter arrived only 8 min later and in relative terms actually kicked a**. The resulting British inferiority complex led to one of the most expensive consequences in yachting history.

 

[flaming]

The speeds of a single boat in something like the ARC don’t give much indication of true performance, for a number of reasons:

• It isn’t a race, so different skippers / crews take different approaches - some fast boats, possibly with young children on board, sail most of the way reefed down, most who are not in a hurry drop kites and possibly add a reef overnight. Other boats, not necessarily fast by nature, are fully crewed with ex dinghy racers and hoist the kite at the Canaries and leave up till the harbour entrance (or possibly on the 2nd or 3rd kite if blown out in a tropical squal.
• Some are paying for weather routing every 12 or 24 hours, from people like Chris Tibbs. This can make a huge difference in keeping in the right wind speeds and avoiding the holes and headwinds.
• A dead downwind route is not ideal for modern asymmetric kite boats, who need to do a lot more distance, whereas most older boats can trundle on at hull speed dead downwind, almost irrespective of sail set.
• etc

I did the ARC on a 45 foot fast cruiser which never hoisted a spinnaker, but went almost the whole way goosewinged with large genoa up, day and night, and was well balanced so generally kept full sail safely through the squalls - and weather routed the whole way. A 40 foot Pogo finished just behind us, but had not been taking weather routing and had covered 1,000 more miles - and blown out their main kite.
The Westerly, Moody, Najad, Malos etc were days behind - but were happy with their trip. Meanwhile we couldn’t quite keep up with a 60 foot classic yawl, sailed like a Volvo Ocean Racer the whole way which “won” overall on handicap.

The “handicap” figures used by ARC are rather more realistic indications - as they represent accumulated experience of 200+ boats sailing this route over 25 years.

Oh I quite agree that the speed of 1 boat is not a good indicator. But then I didn't bring it up...

 

[flaming]

Until a boat starts to plane, if it is at all able to, WL is very much the point in terms of performance.
DWL is a key factor for any number of performance related ratios.

You're still missing the point.
Older boats were designed, for whatever reason, with short waterline lengths compared to their overall length. Today boats are designed with much longer relative waterline lengths. So it is completely expected that the same "type" i.e cruising, racing etc, of modern boat would be expected to be faster for a given overall length. But, in order for you to claim that the newer boat is not faster, you ignore the LOA and insist on only talking about waterline length, and your fixation with this "relative speed" which is something I have only ever come across in discussion with you.

But when people post on this forum something along the lines of "I am looking for a 35 foot boat" they're not talking about LWL are they? So yes, you can say "ah, but this old 40 foot boat only has the same waterline as this modern 36 foot boat, so you should only be comparing it to that". And the buyer says "So to get the same speed potential, I have to pay for much longer berthing whenever I go into a marina, buy bigger sails and bigger deck equipment..?"
So if speed is important to the buyer, and quite clearly it is not to everyone, then buying an older boat looks like an odd choice. And that's before we even start talking about the lightweight boats.

My point about the Pogo 44 was not to compare apples to oranges, it was to point out that this is still an ongoing process. And the boats designed by Pogo, and JPK, and the others are getting better and better at maintaining their speed as they are loaded. Quite obviously the larger the boat is, the easier it is to design a boat that stays relatively light for its load, that's never been disputed.

I highly recommend you to get hold of a copy of the latest Yachting World for the full test of the new JPK39. They talk a lot in that about retaining speed when fully loaded. They put a teaser here.
First look: JPK 39FC – 40 foot French cruiser - Yachting World

 

[geem]

You're still missing the point.
Older boats were designed, for whatever reason, with short waterline lengths compared to their overall length. Today boats are designed with much longer relative waterline lengths. So it is completely expected that the same "type" i.e cruising, racing etc, of modern boat would be expected to be faster for a given overall length. But, in order for you to claim that the newer boat is not faster, you ignore the LOA and insist on only talking about waterline length, and your fixation with this "relative speed" which is something I have only ever come across in discussion with you.

But when people post on this forum something along the lines of "I am looking for a 35 foot boat" they're not talking about LWL are they? So yes, you can say "ah, but this old 40 foot boat only has the same waterline as this modern 36 foot boat, so you should only be comparing it to that". And the buyer says "So to get the same speed potential, I have to pay for much longer berthing whenever I go into a marina, buy bigger sails and bigger deck equipment..?"
So if speed is important to the buyer, and quite clearly it is not to everyone, then buying an older boat looks like an odd choice. And that's before we even start talking about the lightweight boats.

My point about the Pogo 44 was not to compare apples to oranges, it was to point out that this is still an ongoing process. And the boats designed by Pogo, and JPK, and the others are getting better and better at maintaining their speed as they are loaded. Quite obviously the larger the boat is, the easier it is to design a boat that stays relatively light for its load, that's never been disputed.

I highly recommend you to get hold of a copy of the latest Yachting World for the full test of the new JPK39.
First look: JPK 39FC – 40 foot French cruiser - Yachting World

That JPK 39 is owned by a friend of mine?.
if there is anything you want to know about the boat, let me know

 

[flaming]

That JPK 39 is owned by a friend of mine?.
if there is anything you want to know about the boat, let me know

Your friend is a lucky person!

I sail one of its smaller racy sisters. If I ever get to the point of retiring from racing, then it's exactly the sort of boat I'd be drawn to as a cruiser. For now, it's just a pipedream....

 

[dunedin]

Oh I quite agree that the speed of 1 boat is not a good indicator. But then I didn't bring it up...

Sorry, yes, kind of agreeing with you in response to the others doing the usual

 

[dunedin]

.I highly recommend you to get hold of a copy of the latest Yachting World for the full test of the new JPK39. They talk a lot in that about retaining speed when fully loaded. They put a teaser here.
First look: JPK 39FC – 40 foot French cruiser - Yachting World

Yes, coincidentally was just reading that boat test last night. Looks like a great boat, and surprisingly not ridiculously expensive (compared to other boats that size) even in the spec tested with lots of extras including carbon mast.
The must be doing something right, because production apparently sold out for the next two years.
PS. And picking up on some misinformation, the article makes clear these fast cruisers are designed to perform in laden cruising mode. Many do considerable distances.

 

[flaming]

Yes, coincidentally was just reading that boat test last night. Looks like a great boat, and surprisingly not ridiculously expensive (compared to other boats that size) even in the spec tested with lots of extras including carbon mast.
The must be doing something right, because production apparently sold out for the next two years.
PS. And picking up on some misinformation, the article makes clear these fast cruisers are designed to perform in laden cruising mode. Many do considerable distances.

There basically isn't a manufacturer of fast cruising boats without a 2 year wait at the moment.