To A New Paradigm With FPB

FPB 64 Avatar – Final Trial – Part One Of Three

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Since launching we’ve had master aerial photographer Ivor Wilkins on standby for the right conditions to shoot the first FPB 64. The day before Avatar was due to depart for Vila in Vanuatu the appropriate wind and sea state arrived. The photos which follow (with a link at the end to high res versions) were taken in post severe depression conditions.

A 12 to15 foot (4 to 5m) swell is running with wind chop on top created by 35 knots of breeze, gusting to 40. Seas are bouncing off the nearby cliffs, creating a more than usual chaotic sea state. Avatar is at full displacement, carrying full fuel tanks, two dinghies, spares, food, and toys for a season of cruising. This is the ultimate sea trial.

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Avatar is cruising at 9.5 knots in these photos, being slowed to 7.5 when punching through the bigger seas.

We chatted with Rod Bradley, Avatar’s skipper just after the photo shoot to get his impression of the conditions and answer a variety of technical questions for us on how she performed. We’ll cover the performance in more detail with the photos, they are a great learning tool for us, and should be entertaining for you.

Rod is a very experienced  professional, with many thousands of hours at sea in a variety of craft. Prior to Avatar he took care of the Sundeer 64 cutter, Raven, for Avatar’s owners and the previous owners. With this database of experience his evaluation is particularly important to us as designers.

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There are primarily two things about which we are interested. The first is how the bow reacts heading into the seas, and the second is how it handles the same conditions downwind. Rod’s comments in general break down as follows:

  • Much more comfortable than the Sundeer 64 (known as an exceptionally comfortable sea boat).
  • No slamming upwind, even in these larger seas.
  • Good control downwind. No tendency for the bow to lock in and “bow steer”. Not a hint  of wanting to broach.
  • Fifteen to sixteen knots on occasion surfing.

Rod sent us an e-mail today about the passage to New Hebrides. His brief comments were “We left in 30 knots from behind….huge sea from a sub tropical low just passed , easterly set. super comfortable, stern getting slew around at times. 36 hours out wind eased to 10 knots south, now 5 to10 knots south, messy sea still. The busiest we were yesterday, was to turn the nav lights off and then on again. Weather looks light the rest of the way, a dream trip, by the looks of it. I know why motor boat captains are fat and drink alot…..there is nothing else to do !!!! Overall very impressive.”

We hope to have an update from Rod when he gets to Vila after his first long passage aboard the FPB 64.

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Ivor Wilkins is the premier marine photographer in New Zealand and one of the best in the world. He is the source of the wonderful photos of Wind Horse and Beowulf which you have seen on so many magazine covers and on this website. Ivor has photographed every imaginable type of yacht in all sorts of conditions, so his observations below from the helicopter are of interest.

The waves were confused, with some big sets coming through at times. Wind speed was gusty and I don’t have any quarrel with 35 knots. In terms of the helicopter: It was one of the more precarious rides. Flying out to rendezvous with the boat, we got hit by some pretty vicious gusts, which had me clutching the door frame (there being no door on at the time). Our original plan was to shoot closer in to the cliffs to get some backdrops, but it was very clear that there were some very strong downdrafts and the turbulence was too unruly. Even over open water, the pilot had his hands full trying to keep on station and there was no way he could hover downwind — the tail would just spin out. He did a great job in working in close at times – maybe a bit close for Rod’s comfort. He said he was about to get the fenders out at one point!”

“The boat was impressive. Punching upwind, you could see the bow working very well, driving into the waves but very quickly shrugging off the water. It never appeared to stagger or lose momentum, even with some short, nasty seas. When it was running across the seas, the stabilisers were clearly doing an excellent job, because it all looked very docile (almost too boring to photograph) with minimal side roll. Running downwind looked very comfortable with the boat holding a very steady course and showing no inclination to slew or wallow. She would pick up on a wave and just accelerate forward, with the bow occasionally popping out. Looked like a nice spinnaker ride, the kind that chews up big daily mileages.”

“I would say that some of these shots will be added to my all-time favourite boat pics, just for the drama of the action. Incidentally, I would include the spinnaker shot of Beowulf in that list as well.”

Perhaps the most telling comment from Ivor was about what he found aboard when he met Avatar as she came back to her dock in Whangerie, New Zealand. Rod had already cleaned the salt from the windows, the deck was organized, and she was neat and orderly below. Art work and bedding were still in place in the  Owner’s suite forward and there was not a hint of leakage from the water on deck.

OK, on to the photo analysis. We hope you have a few minutes as there is a lot to  cover. Keep in mind Ivor’s comments about sets of bigger seas. In the photos which follow we concentrate on the biggest, most unpleasant of them, as that is what we want to be optimized for.


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This series of photos show Avatar dealing with a larger than usual set of waves. What we are interested in as designers is how the distribution of volume in the ends reacts to the lift of the seas. In this shot of particular interest is the stern buoyancy. Note the angle of the boat relative to the wave face here and in succeeding photos. Avatar is pitched up, but she is matching the shape of the wave face. There is no evidence of hobby horsing.


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The wave barely has a grip aft. If the stern was wider,  the wave would react against it and force the bow deeper into the oncoming crest.

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Now the bow. Although this looks dramatic there is actually very little water coming aboard and the motion, relative to boat speed and sea state, is benign. Ivor shot these photos with a high speed motor drive on his full frame Canon body. The seven photos cover between one and two seconds of elapsed time.

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This is a particularly interesting shot. The boat is 80% airborne. Rod will be amazed when he sees these as he has no idea from the motion aboard there is this much boat out of the water. The design goal is to soften the landing to keep the ride at a reasonable level of comfort, while still maintaining downwind control.

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The next couple show bow and stern reacting to the old (aft) and new (forward) waves.

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Again, dramatic looking, but note the magnitude of the spray and water on deck. Any volume added to the aft end would now be forcing the bow down into the oncoming crest.

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This is the result of the bow and stern working together.

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A close up of the bow from the previous photo.

Now another set, this time with a somewhat steeper wave than the previous, shot from a different angle.

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Waves by their nature are chaotic. Occasionally there will be a bigger wave set of waves, or an unusual crest. It is that “unusual” situation for which we want to be prepared. This has to be taken into account with furniture layout, fiddle and handrails, structure, glazing, engine and prop, and of course, hull shape. The photo above represents 95% of what a day like this will typically show you. Then you have those other waves.

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Now it gets interesting.

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This is not an everyday occurance. If Rod were not testing the boat one final time and posing for Ivor’s camera, he’d not choose to be out in these conditions. But he knows that you do on occasion get caught. All those elements we have discussed in this blog and elsewhere now come into play. Hatch specification, Dorade vent design, window structure, even anchor roller design are going to be tested.

This does look dramatic, but study just how much water is actually on deck. Not that much in terms of volume or weight.

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OK, that one is past, the deck has little water left (this series of photos takes place over about a second), and we are ready for the next wave.

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Above is a close up of the preceding photo. It looks dramatic, of course, but the actual magnitude of solid water is minimal. Note the Vetus PVC cowls are still in place, a good indicator of the force of the water coming down the deck.

Nobody likes going uphill, especially us, so we want the most comfortable ride possible when heading into the waves. But if you design just for upwind work, the boat becomes hard to control downwind. This is uncomfortable, to say the least, and  potentially dangerous if steering is lost leading to a broach and capsize. As you have no doubt noted from previous blogs, we, and our owners, also like to surf.

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Now some context. If you are on a long downwind passage, the same seas we’ve been fighting uphill become fun, and look a lot smaller.

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As you can see from the flag, the wind is almost dead astern.

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Downwind control, and enjoying the surfing, is all about the distribution of bouyancy along the hull, bow immersion and its tendency to lock in and steer the boat, and rudder size relative to the work load. Keep in mind when looking at these photos that Avatar is as heavily loaded as she is ever likely to be.  She is just starting to take off on a wave.

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Although the FPB 64 is very fine forward, and penetrates the waves  upwind, she still has enough bouyancy spread out in her forward sections to support her downwind, and help keep the bow from locking in.

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She probably displaces 43 or more tons here, yet she can get her bow out with dynamic lift and native buoyancy.

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We hope we are not boring you with our enthusiasm. It is extremely rare to see a yacht at work like this, and while we have experienced this many times aboard, seeing it from the perspective of the helicopter is wonderful.

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A couple of photos now to show bow and stern working together. That relationship is even more important downwind. A fat rear end shoves the bow down into the wave ahead as the sea  overtakes you from astern. It also makes the boat harder to steer.

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We’ll leave you with a few more details.

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Rod and Niko driving from the flying bridge, and thinking about tropical lagoons. When we chatted with Rod a few days ago we warned him about the FPB turning him soft. He said it was too late. He was now a firm believer in staying comfortable, warm, and dry.

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A particularly nice photo.

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And then a good overall photo of a cruising “tool” with its two dinghies, protected flying bridge, and clean foredeck.

To see these photos full screen click here.


Posted by Steve Dashew  (July 19, 2010)




17 Responses to “FPB 64 Avatar – Final Trial – Part One Of Three”

  1. Bob & Cherri Says:
    WOW! You hope you are not boring us with your enthusiasm?! Not a chance!…..in fact we would love to have much more!! After all the theory & design, this really brings it to life. …..you wouldn’t have motion video you’re going to treat us to, would you? I can’t tell you how much I’ve learned by following all this for the last….how many months? Please keep it coming! Bob

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  2. Dave Says:
    Wow. These are great photos! Especially the airborne shot. Now we know what a hydrofoil FPB would look like underway. :) (Hmm.. If she did have foils, would she have enough power to get up on them?) Thanks for sharing these with us. Dave

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  3. Scott Says:
    At last, an update, and it was worth the weight. Beautiful to watch the hull doing its thing! “Well Done” Steve and team, that hull works so well. My favourite photo(now my screne saver) is the underneath view of the hull!!!! Talk about getti some hang time. I’d also like to echo the other comments, that was VERY educational. thankyou Scotty

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  4. Scott Says:
    Last photo, the bbq cover is missing. left it off? or did mother claim it? Scotty

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    Steve Dashew Reply:

    Hi Scotty: Not sure of the answer, but my guess would be Rod stowed it.

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  5. Carlos V Sucre Says:
    Great pics. second Bob&C !not a chance¡.and yes its been a learning experience. Hope for video. And congratulations. No doubts the FBP concept is something special. Thanks for sharing Carlos

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  6. Mike O'Reilly Says:
    I just sent this page link to my Facebook site that is infested with serious offshore performance sailors. I’ve been following you (secretly) for a few years and this is a brilliant concept for serious sailors who want to continue living on the oceans. Great work. Thumbs Up. Mike O

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  7. Jim Jensen Says:
    WOW is right! I want one! More please! Let that go to your head… you are the best!

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    Steve Dashew Reply:

    Thanks for all the positive feedback. We’ll have another set up in a day showing what things look like the majority of the time in this sort of weather (the photos in this blog being the worst of it).

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  8. Bo Leonard Says:
    Steve Is the door to the salon open in those upwind photos? GREAT shots, you must be a proud pappa. Bo

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    Steve Dashew Reply:

    Hi Bo: Yes, the main watertight door is open, which indicates the crew’s level of non-concern with the sea-state.

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  9. Scott Says:
    need a deckie?

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  10. Jason Fimrite Says:
    Steve, Hello from northern Alberta! The 64 looks great; amazing photos, very clean and capable craft. Typical Dashew professionalism. Congratulations Steve, Linda and team.

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  11. Matt Marsh Says:
    This is really quite a nice set of photos. It is great to be able to see the boat at work like this, in her element and behaving as your calculations predicted. I find it very refreshing to see such a well balanced design. I don’t much care for the marketing trends surrounding cruising powerboats in general- the hype is always about more systems, more computers, more living volume and more endangered hardwood joinery. We have, somehow, come to expect that a 60-footer will have 1500 square feet of living space on two decks and that it will be shaped like a brick from station 4 aft. This is wrong, and I think you’ve made a convincing case with the FPBs for a more carefully engineered, more balanced approach. Your comments on the fore-aft distribution of hull volume are well taken. This is a perpetual problem in the smaller, planing-hull boats I typically find myself in; the voluminous aft sections that give these boats their calm-water speed, combined with bows that aren’t meant to touch the water at all, create a handling nightmare in rougher seas. I’m starting to think that one really ought to look at separate fore and aft Cp and Cwp as well as the whole-hull coefficients when evaluating a boat’s stats. Plus, of course, the curve of areas, that important little graph that is often so hard to find. Avatar is far too much boat for me at the moment, both in size and in cost. I do admire what you’ve done here, though, and I hope the concept will prove inspiring to other designers as well.

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    Steve Dashew Reply:

    Hi Matt: I am not sure about other designers, but we look very carefully at the prismatics of both ends.

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  12. Ben Garvey Says:
    Hi Steve and Linda – looks fabulous- very impressive – as we all expected. You truly are still breaking amazing ground here. Was discussing this with an engineering colleague today and we both were wondering about the dynamic loading on the stabilizers in those conditions. I don’t imagine the stabilizer folks talk about their fins going airborne and then slamming down into the sea in their sales brochures, but I’m sure it’s something you’ve considered. Can you comment on the unusual loadings here and your level of comfort in relation to this type of loading in these conditions? Also, does the presence of the bow thruster and tunnel in this hull make an appreciable difference in terms of noise and slamming when pushing uphill like this? there has to be some effect from its presence, but is it noticeable? regards, bg

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    Steve Dashew Reply:

    Hi Ben: The deceleration loads are actually pretty soft. On Wind Horse, which has a somewhat harder ride, the most we have measured amidships is seven tenths of one G. These are rather small fins for their shaft size as well. The bow tunnel is a definite drag producer, probably on the order of one percent of the total for the boat (guessing here), but does not appear to be a significant noise producer.

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Comments or Questions?