Pocket cruising boats

Discussion in 'Sailboats' started by Guillermo, Apr 30, 2006.

  1. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    Thanks for the link, Paulo. Nice little boat. Love the styling.
    Here some info on it (The kinda' you don't like :) )

    LH = 8,3 m
    Lwl = 7,79 m
    Bmax = 2,7 m
    Bwl = 2,21 m
    Draught = 1,7 m
    HD = 0,4 m (guessed)
    Disp = 2800 kg (Light...medium...full load???)
    Ballast = 1200 kg
    Sail area = 33,5 m2
    Power = 11,5 HP

    Displacement /Length Ratio D/L = 165,21
    Sail Area /Disp. Ratio SA/D = 17,14
    Power / Disp. Ratio 6*HP/D = 11,17
    Hull speed HSPD = 6,77 Kn
    Potential Maximum Speed PMS = 7,62 Kn
    Velocity Ratio VR = 1,12
    Capsize Safety Factor CSF = 1,93
    Motion Comfort Ratio MCR = 19,9
    Screening Stability Value SSV = 37,36
    Angle of Vanishing Stability AVS = 124,62 º

    Roll Period T = 2,37 Sec
    Roll Acceleration Acc = 0,11 G's
    Stability Index SI = 0,88

    Seems also quite more acceptable than the Seaward 26 to me.
     
  2. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    I respect those opinions. But remember I'm giving you my humble experience as surveyor, not opinions.
     
  3. Vega
    Joined: Apr 2005
    Posts: 1,606
    Likes: 26, Points: 58, Legacy Rep: 132
    Location: Portugal

    Vega Senior Member

    Don't take me wrong, I understand what you are saying. What I want to mean when I have said:” I guess that what makes the right 27ft cruiser depends on the order of the criteria that are important to each sailor.” Is that the criteria (and the order) you chose as relevant to judge a 27ft, would be the order and criteria that I would probably consider relevant to a boat for a circumnavigation.

    Of course, if you want to cross oceans in a 27ft, then I would follow your criteria, but people don’t buy 27ft to cross oceans….

    As I have said, there is no right or wrong here, just different criteria to judge a boat.

    About the market, this boat, the “Pantanal 25” by Roberto Barros seems to answer to what the market demands from a pocket cruiser: An inexpensive boat with a spacious interior, a trailerable and fast boat with a small draft. For having a small draft and still have a big initial stability (for being fast) the generalized answer is a bulb in a movable keel.

    http://www.yachtdesign.com.br/02_ingles/index_ingles.htm
     

    Attached Files:

  4. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    Paulo,
    Here data for the Pantanal 25:

    LH = 7,65 m
    Lwl = 6,66 m
    Bmax = 2,44 m
    Bwl = 2,2 m
    Draught = 1,5 m
    HD = 0,28 m (guessed)
    Disp = 1500 kg
    Ballast = 320 kg
    Sail area = 30,38 m2
    Power = 6 HP (Outboard. Guessed)

    Displacement /Length Ratio D/L = 141,63
    Sail Area /Disp. Ratio SA/D = 23,56
    Power / Disp. Ratio 6*HP/D = 10,88
    Hull speed HSPD = 6,26 Kn
    Potential Maximum Speed PMS = 7,97 Kn
    Velocity Ratio VR = 1,27
    Capsize Safety Factor CSF = 2,15
    Motion Comfort Ratio MCR = 13,93
    Screening Stability Value SSV = 89,13
    Angle of Vanishing Stability AVS = 115,05 º

    Roll Period T = 1,51 Sec
    Roll Acceleration Acc = 0,24 G's
    Stability Index SI = 0,62


    Interesting trailerable boat, quite racy, adequate for short good weather sailings, but not for long term cruising.

    What I'm trying to discuss are seaworthy coastal boats able for long term cruising. Most of the cruising done in coastal waters, for sure, but the boat has to be able to handle severe punishment when necessary, having short seas passagemaking capability. Category B is enough to that end, in my opinion, but not Category C. Category A is a bonus as it allows for longer passagemakings, maybe not oceans crossing (or...why not?) but let's say 400-500 miles open sea hops (This is around 3 days in most cases, which allows for a high confiability weather prediction, although....)

    Also reviewing my first post:

    PILOT CUTTER 30:

    LH = 9,14 m
    Lwl = 7,85 m
    Bmax = 2,89 m
    Bwl = 2,6 m
    Draught = 1,6 m
    HD = 0,6 m (guessed)
    Disp = 6350 kg
    Ballast = 2200 kg (guessed, asked Select yachts, waiting for answer)
    Sail area = 55,64 m2
    Power = 29 HP


    Displacement /Length Ratio D/L = 366,14
    Sail Area /Disp. Ratio SA/D = 16,49
    Power / Disp. Ratio 6*HP/D = 12,42
    Hull speed HSPD = 6,8 Kn
    Potential Maximum Speed PMS = 7,38 Kn
    Velocity Ratio VR = 1,08
    Capsize Safety Factor CSF = 1,57
    Motion Comfort Ratio MCR = 39,74
    Screening Stability Value SSV = 34,49
    Angle of Vanishing Stability AVS = 126,33 º

    Roll Period T = 3,79 Sec
    Roll Acceleration Acc = 0,05 G's
    Stability Index SI = 1,31

    Design Category: A

    Now, this is a hell of a boat!
     

    Attached Files:

  5. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    Now let's discuss the motorsailer concept, based on a classic: The CAPE DORY 300 (http://www.toolworks.com/cdsoa/specs/cd30ms.htm)

    Here data for her:

    LH = 9,1 m
    Lwl = 8,08 m
    Bmax = 3,48 m
    Bwl = 3,13 m
    Draught = 1,19 m
    HD = 0,5 m (guessed)
    Disp = 5212 kg
    Ballast = 2040 kg
    Sail area = 44,31 m2
    Power = 30 HP

    Displacement /Length Ratio D/L = 275,58
    Sail Area /Disp. Ratio SA/D = 14,98
    Power / Disp. Ratio 6*HP/D = 15,65
    Hull speed HSPD = 6,9 Kn
    Potential Maximum Speed PMS = 7,29 Kn
    Velocity Ratio VR = 1,06
    Capsize Safety Factor CSF = 2,03
    Motion Comfort Ratio MCR = 25,01
    Screening Stability Value SSV = 53,42
    Angle of Vanishing Stability AVS = 119,21 º

    Roll Period T = 2,38 Sec
    Roll Acceleration Acc = 0,16 G's
    Stability Index SI = 0,68

    She has quite a high Acceleration number and low SI, so probably uncomfortable when in wavy seas. She is quite beamy. On the other hand the pilothouse concept allows for a dry and protected steering in colder climates, and her rear cockpit integrated with the wheelhouse provides a very nice living area when at port or anchor. Wheelhouse also allows for the cockpit to easily be covered by a tent, providing extra sleeping bunks at night when in good weather. Maybe something like this, less beamy and Category B designed, could be a very nice option. Abating mast, a bonus.
    On top of it, as motorsailers are not very sail efficient, probably a lower aspect ratio rig, like the gaff one, could be more appropriate, in line of Paul Gartside boats. A pity he has not motorsailers designs in this range (Anyhow have a look at: http://www.gartsideboats.com/catsail6.php#37mtrsail)
     

    Attached Files:

  6. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    More about the Frances 26:

    http://www.chuckpaine.com/pdf/26FRANCES26.pdf
    http://francis26.org/

    LH = 7,57 m
    Lwl = 6,47 m
    Bmax = 2,54 m
    Bwl = 2,29 m
    Draught = 1,17 m
    HD = 0,5 m
    Disp = 3082 kg
    Ballast = 1600 kg
    Sail area = 32,1 m2
    Power = 12 HP

    Displacement /Length Ratio D/L = 317,4
    Sail Area /Disp. Ratio SA/D = 15,4
    Power / Disp. Ratio 6*HP/D = 10,59
    Hull speed HSPD = 6,17 Kn
    Potential Maximum Speed PMS = 6,68 Kn
    Velocity Ratio VR = 1,08
    Capsize Safety Factor CSF = 1,76
    Motion Comfort Ratio MCR = 27,76
    Screening Stability Value SSV = 21,78
    Angle of Vanishing Stability AVS = 143,96 º

    Roll Period T = 2,7 Sec
    Roll Acceleration Acc = 0,08 G's
    Stability Index SI = 1,06

    "Chuck Paine’s adored his first FRANCES. She was beautiful, well mannered, stable, and just plain fun. She possessed timeless virtues that seem to have disappeared from the modern world. Narrow of beam, her sleek lines overcame resistance like a dreadnaught. Set her in a straight line toward a destination and she was unstoppable."

    Hats off...! :)
     
  7. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 189, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    Well, it seems I'm getting alone in this thread, but anyhow...
    Here some basic design and most interesting ideas for a pocket cruiser from the Pocket Cruiser Design Competition:

    "Most of us who sail small boats have a picture in our mind’s eye as to the perfect little cruising yacht we would like for ourselves. I frequently dream of such a boat. But where do we start? I don’t normally make lists, but in order to build up a picture of what is required, I have come up with some things that may be considered when approaching a design.
    Expected use of the boat: Daysailer; weekender; channel hops or extended long-distance cruises. You and the boat will have to be self-reliant and self-suffi cient in any circumstances.

    Everything onboard needs to be reliable and robust.
    Number of crew: Single-handed; a couple; three crew or more, enabling a watch system to be maintained on extended passages.
    Where will the boat be kept: Marina; drying mooring; swinging mooring or trailerable.
    Size of boat: Length, beam, draught and displacement; these will tend to grow as you try to squeeze in much of the list below. It’s worth noting that a boat of 26ft will have approximately 50 per cent more displacement and cost twice as much as a boat of 20ft.

    Seaworthiness: The ability to ride out a gale, even when coastal cruising. Stability and trim.
    Construction: Traditional wood; wood epoxy; plywood epoxy; steel; aluminium; glassfi bre or composite. Adequate scantlings.
    Ballast: Internal or external; lead or iron; centreplate, bilge plates or fi n and bulb.
    Rig: Gaff; gunter, lug, bermudan; junk; sloop; cutter; ketch or yawl.
    Mast construction and rigging; reefi ng systems. Sail areas and centres of effort. Sheet winches.
    Steering: Tiller; wheel, pedestal, hydraulic or cable; emergency steering; self-steering.
    Aesthetics: One of the most important aspects of any boat, it has to look good!
    Safety: Self-draining cockpit; washboards; adequate bilge pumps; secure hatches and portholes; escape hatch; liferaft or tender; grab bag; grabrails; lifelines and stanchions; gas and bilge alarm; fi re extinguishers; fi rst aid kit; radar reflector; danbuoy; lifebuoy.

    Engine: Electric motor; diesel inboard or petrol outboard.
    Engine access; exhaust runs.
    Tanks: Fuel and water for intended use + 25 per cent; grey and black water holding tanks.
    Gas: Dedicated draining locker for gas bottle plus spare.
    Electrics and electronics: Batteries; navigation lights; internal lights; pumps; VHF; GPS; EPIRB; plotter; log, compass, sextant etc; solar panels; wind generator.
    Galley: Cooker; sink; cool box; fridge; worktop; cutlery and crockery; pans and food storage.
    Storage: A locker for each crew member’s personal belongings; hanging locker; lockers for bedding; lifejackets; flares; charts; sails; tools and spares. Deck lockers: warps;fenders; legs; liferaft; tender; spare fuel and water cans; anchors and ground tackle; chain locker.
    Windlass: Desirable on larger boats.
    Chart table: Desirable if there is enough space.
    Table: Again, desirable if there is enough space.
    Berths: One for each intended crew member.
    Seating: Enough for each crew below and in the cockpit.
    Wet locker: Oilskins and wellies.
    Sanitation: Sea toilet; chemical toilet; bucket and chuck it; handwash sink; shower.
    Ventilation: Opening hatches and portholes; engine vents; dorade or mushroom vents; locker vents.
    Natural lighting: Skylights; portholes and deck prisms.
    Heating: Solid fuel; gas; diesel; paraffi n or radiators.
    Tender: Traditional or infl atable. Tender outboard?
    Canopy: To keep dry and out of the wind, and to protect an open companionway from spray. Sun canopy.

    This isn’t meant to be a definitive list of what needs to be included in the design of a pocket cruiser, but I hope it will act as a reminder of the individual elements that go into making a seaworthy design. It isn’t until you see a list such as this that you realise the compromises that have to be considered, and the problems designers face – and this is only at the preliminary stage
    of the design. This is before the calculations for displacement, trim, stability, scantlings, sail area, centre of effort and centre of lateral resistance have been factored in. Finally, one of the most diffi cult calculations if you are working within a budget is that of cost. It may be better to design a basic but sound boat initially, and then add the expensive extras when finances permit."

    Really good. I only would add, why not a wheelhouse?

    Cheers.
     
  8. DanishBagger
    Joined: Feb 2006
    Posts: 1,540
    Likes: 46, Points: 0, Legacy Rep: 523
    Location: Denmark

    DanishBagger Never Again

    Nice "compilation" :)

    Definately got me thinking, and by using your list, that mental picture can be summed up like this (I wouldn't want a wheelhouse, though - both becaus of windage, but also because, imo, it's easier to sail when I can feel the wind):

    Two people.

    Not trailerable (unless it happens to be that, but not as a criteria). Swinging mooring.

    I am thinking 24ft or thereabouts.

    Certainly. A swing keel, and a combination of internal/external ballast (I will get around to that). Easy to handle, possibly with the type of rig of romily and roxane.
    Wood-epoxy. The reason for this is strength. Then a bit more weight can be used for ballast.


    Here I would go for a leaded swing keel. Some leaded external ballast, and use batteries as internal ballast.

    I think the Romily/Roxanes are yawl rigged? But I would actually prefer to have a single sail, kind of making it a lug-rigged catboat. That way it would be easy to install a self-steerer.

    I would want the gaff to be carbon fibre, the mast _could_ be a strip-planked wood-epoxy construction (to save money, but I would prefer CF). I would want a boom, though.

    Certainly tiller-steering. Self-steering would optimally be an "in-built" Cap Horn self-steerer-

    Yup, nice and low. I don't care about standing height that much, frankly.

    Manual bilge pumps all around. No traditionally self-draining cockpit (with hoses), but old-school where you sit on "boxes", and the cockpit sole is actually the deck.

    If an engine were to be installed (not sure I wanted that), it would have to be an electric one. Also, it would have to be able to re-generate.

    No fuel-tanks.

    I don't like gas. Actually, it scares me a bit. I would want either an Origo (alcohol), or a Taylors K-lite (kerosene). Both for safety, but also because it's easy to get the fuel.

    .
    Well, yes - except for the epirb and plotter.

    Manual pumps. Saltwater and freshwater pumps at the sink. No fridge, but a cool-box. Manual pump to empty the sink.

    I don't think each person would need a personal locker. I just think they need "a corner", so to speak.

    Yup, I would want something nifty designed, where, for example, a "lid" could be put on top of the stove or something like that.

    Don't need it, or want it. I figure that it would make the boat wider.

    Yup, and proper sea-berths.

    Yup.

    No shower. Certainly a toilet (I wouldn't be able to get my better half to sail for even three months without one).



    Mushroom vents, dorade boxes. The locker vents .. I would want a simple hole in the lockers (the ones inside), and have the back of the lockers sides have holes along the hull.

    Deck-prisms. And one long skylight, rather like "EVA", if you have seen that one.

    Solid fuel. The black one from Daveys. Nice size. Also, two lanterns to make heat barriers at the openings.



    Oars, and a simple sail. It would be a folding one (plywood+cordura).

    Certainly. And the spray canopy should be sort of "inbuilt".



    Heh, man, I want to build one, now :p
     
  9. DanishBagger
    Joined: Feb 2006
    Posts: 1,540
    Likes: 46, Points: 0, Legacy Rep: 523
    Location: Denmark

    DanishBagger Never Again

    Ooh, I forgot: I also want to have oars on the "big" boat.
     
  10. Jonas63
    Joined: Oct 2005
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Portugal

    Jonas63 Junior Member

  11. Wellydeckhand

    Wellydeckhand Previous Member

    I think Guillermore is thinking of a bigger picture here:) Nice job........ There bound to be a lot of someone praising you for your indirect help:)

    WDH
     
  12. Jonas63
    Joined: Oct 2005
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Portugal

    Jonas63 Junior Member

    :confused: :confused:

    Vega and others had posted links to commercial plans on this post before, why should someone praise my indirect help ????

    Also like the Roberto barros pantanal design posted before...
     
  13. Wellydeckhand

    Wellydeckhand Previous Member

    Sorry, I was commenting on his previous post on mental preparation of dream boat.

    Vagabond is trustworthy desigh, dont worry........ in -movie 50 first date - they use Vagabond I think:)

    WDH
     
  14. fcfc
    Joined: Feb 2005
    Posts: 781
    Likes: 29, Points: 28, Legacy Rep: 399
    Location: france,europe

    fcfc Senior Member


    The big problem of Jacques mertens designs Vagabond 20 and 26 is that designs Primo, Pizzicato and Dingo from french Naval Architect Jean Pierre Villenave existed about 20 years ago.
     

    Attached Files:


  15. Jonas63
    Joined: Oct 2005
    Posts: 5
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Portugal

    Jonas63 Junior Member

    Well... living and learning, it´s almost an exact copy

    thanks for the post

    I like the dingo :)
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.