Bob Perry

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Bob Perry last won the day on October 28 2017

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  1. Bob Perry

    Coolboats to admire

    The Watt&Seas are very efficient and used on a lot of racing yachts. Yes there is some drag. But they articulate to stay aligned with the flow, kind of like a rudder. During trials on No. 1 we noticed no change in boat speed with both Watt&Seas deployed. And believe me, we were paying attention. If they make no sense to you you can leave them off your boat. We like them. We got 40 amps out of two units at 9 knots. We found that impressive.
  2. Bob Perry

    Coolboats to admire

    Brackets for Watt&Sea hydro generators. Wa 2 by robert perry, on Flickr
  3. Bob Perry

    Coolboats to admire

    Carbon cutter No. 2 getting ready to be sailed for the third time. 006 by robert perry, on Flickr
  4. Bob Perry

    Dick Carter design boats

    I think you will really enjoy this book JohnB.
  5. Bob Perry

    Carbon cutter No. 2

    Full keel boats are almost always miserable in reverse. It's hard to eliminate the prop walk when you funnel that directional flow through the aperture. The only solution I have found is to use a Max Prop. The blades of the MP are symmetrical and as efficient in reverse as they are in forwards. The Max Prop can reduce the problem but will not eliminate the problem. On the carbon cutters I was hoping with that unusually large aperture that the bat would be docile in reverse. All I know so far is No. 1 with the Gori is pretty good in reverse and No. 2 with the Autoprop is awful. I'd really like to try No. 3 with a Max Prop. The very best boats for control in reverse are race boats, with short chord keels and clean spade rudders. The more shit you hang under the boat aft there more the chance that the boat will not behave in reverse. Some of my cruising boats with skeg hung rudders are very good in reverse. But no skeg is better. Bottom line is that lack of control in reverse is potentially the biggest problem you will have with a full keel boat. Think bowthruster!
  6. Bob Perry

    Carbon cutter No. 2

    Yep.
  7. Bob Perry

    Carbon cutter No. 2

    Left: The light and very shifty air you get on the Duck Dodge should give AIRLOOM all the street cred it needs. Here's anther Baba 40 that has been racing and winning on the East Coast this year. Baba 40 racer by robert perry, on Flickr
  8. Bob Perry

    Carbon cutter No. 2

    Left: Sorry but you need to get some experience with a well designed modern full keel boat. You generalize way too much and display your ignorance. There are many of my full keel boats competing and winning. You might check out AIRLOOM. Then there is Jeff who sailed his Baba 40 single handed, non stop around the world. But I won't even go into that. Those duck decals on the stern are not for losing. Airloom heeled stern by robert perry, on Flickr
  9. Bob Perry

    Carbon cutter No. 2

    Mooks: Yes. I designed that keel as a long fin with an NACA foil. It took several dog walks for me to decide just how thin I would make it. I probably could have gone with a 7% thickness ratio. I've never gone that thin on a long keel before nut I think it would work. But in this case I needed volume in the fin for the ballast and ALL the tankage. So after a few dog walks and many pipes I chose a 9% thickness ratio. I used quite a bit of sweep to the leading edge to help the keel. Log chords don't play well with vertical leading edges. You have to coax the water to stay attached to your foil and not just take the easiest way out and shoot under the tip with a big vortex, i.e. drag. I chose gentle.
  10. Bob Perry

    Carbon cutter No. 2

    Shirley: The choice of full keel has nothing to do with where you live. It's just a personal decision. I have done many many offshore cruising oats that do not have full keels . My own preference would be for a fin and a spade rudder. But I am not the client. Some sailors just feel a full keel, in it's various forms, is safer.In their mind. it's never gong to fall off. Of course the well designed fin keel won' fall off either. But try telling them.
  11. Bob Perry

    Carbon cutter No. 2

    Longy: I think we save d about 1,000 lbs with the battery change. We made an adjustment to the ballast slugs also so we are about 1,500 lbs. lighter than No. 1. No. 1 was launched with an empty focsle. No. 2 had the focsle loaded at launch. Client was in charge of prop selection. I've been adamant that a Max Prop was the way to go but my advice falls on deaf ears. Not sure what will happen to the Autoprop. Can't imagine it will stay on the boat. I'l let you know. Bigrpowr: Yes, we have polars and full VPP tables. I haven't done a new design for over 20 years without VPP's. It's just part of the process now. Mooks: You would think that by now"full keels" would have gone the way of bias ply tires. But no. There are still a die hard bunch of cruising sailors who believe the safest sailboat is one with a full keel. Considering the "my keel fell off and I can't get up!" stories we read these days I can understand.They see a full keel with internal ballast as the safest way to go. In this case it was part of the design brief from the first few minutes wit the client. "I want a full keel, like my last boat." What I tried to do was give the client the most effective "full keel" I could that would meet his criteria. I failed on my first attempt. The client wanted the leading edge further forward. I moved it. It's my job to give the client what he wants while making sure it works well. The treatment aft with the outboard rudder and "chastity strut" was part of the effort to reduce the chord of the "full keel" and allow for a big rudder with some balance area. I wanted a gentle feel on the tiller.
  12. Bob Perry

    Carbon cutter No. 2

    JM: The carbon cutters are my variation on the Brsitol Channel Cutter theme. Thanks Lasal. Just another day at the office.
  13. Bob Perry

    Carbon cutter No. 2

    Foamy: I have done the same thing on many boats. But in this case we were out for a quick initial sail on the boat and there was a lot going on. For longer trips the lazy jacks would be stowed at the gooseneck. I have way that they can "autostow".
  14. Bob Perry

    Carbon cutter No. 2

    Thanks Beer. Don't think I have ever sailed on a boat with a bow pulpit when the headsail does not drape over it at some point when you crack off. Sure, some cruisers like to raise the tack up above the pulpit but I like to keep the tack as low as possible. Overlay needs to go sailing. The boat sails extremely well. Granted it's no TP52 but as a traditionally styled cruising boat it has shown very good boat speed. And yes, this is a custom design and the owner requested a traditional "look". That's what he likes. That's what he got. Cal20: The sail inventory is identical to No. 1 as far as I know. I'll ask when we go out with Jack next week. Darth: The boat in the background is WALL STREET DUCK. I believe it's a Wiley design from SF. I'm sure someone here knows. It's in pretty rugged condition and has been sitting like that for at least a year. Looks to be a nice boat. Hope someone brings it back to life. DSC_6680 by robert perry, on Flickr
  15. Bob Perry

    Carbon cutter No. 2

    Lazy jacks are not tensioned. I think we all know better than that. I prefer they are not flopping around. Tight enough not to flop, loose enough not to cut into the mainsail. Not difficult at all.