FS14: Seaworthiness? Other considerations?

Discussion in 'Boat Design' started by Tapio Peltonen, Aug 11, 2009.

  1. Tapio Peltonen
    Joined: Aug 2009
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    Location: Turku, Finland

    Tapio Peltonen Junior Member

    I'm planning to build a small outboard-powered planing boat from plans to replace my current boat. My current boat is 4.5 m LOA, planing hull, moderate vee, wooden open boat that has been fiberglass coated on the outside in the 1970s. It is fairly stable and seaworthy for its size, but I don't know if this has to do more with the fact that it's very heavy than its shape.

    My SOR for the boat: It is for short distance (a few km) travel in semi-protected waters in the Finnish archipelago. It has to be cheap and easy to build as an amateur. It has to be able to stay upright and in one piece and travel short distances in sea state 3, preferably with some safety margin (no need to be able to keep the passengers dry in a foul weather though). It has to be able to carry at least 4 average-sized people with some luggage. It has to have a planing hull and preferably be able to plane fully loaded with less than 20 hp.

    My current boat satisfies most of my requirements, but the wooden parts are remarkably rotted. I need a replacement before my current boat falls apart on its own.

    I have looked at the stitch-and-glue plans available for sale, and bateau.com's FS14 looks promising:

    http://bateau.com/studyplans/FS14_study.htm?prod=FS14

    It's a bit shorter and much lighter than my current boat, though. Any opinions? Is this seaworthy enough? Do I need ballast weight if I travel in bad weather with the boat lightly loaded?

    The FS14 attracted my eye because of its simplicity and the fact that it looks quite a bit like my old boat. Is it a good idea, or would I be better off with some other design? Should I go straight for a bigger boat?
     
    Last edited: Aug 11, 2009
  2. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Hi Tapio, welcome aboard :)

    It's nice to see someone who's already thought through his requirements.

    The FS14 looks like she would do well in fairly calm conditions; a pretty versatile general-purpose skiff. She has a fairly deep, flat forefoot which may make it difficult to power into a head sea.

    If I may put in a shameless plug for the Phil Bolger plans that my own runabout is built from:
    http://www.instantboats.com/diablo.htm
    Diablo is quite easy to build, and is very comfortable (and quick) in conditions up to Beaufort 3. I have had mine out in conditions as bad as the bottom end of Beaufort 5, and she is still safe, stable and reasonably dry in these conditions. She will easily carry 4-5 people with their gear, and works just fine with 15-20 hp. Don't be fooled by the apparently flat bottom- at lower planing speeds, or with heavier loads, it's the fine, sharp V of her forefoot that is cutting the waves.

    The Bolger/Payson "tack and tape" method is similar to stitch and glue, but the panel curvatures are matched in such a way that the wire-stitching step is eliminated. Everything mates up beautifully just by bending the panels into position.

    Any small planing-hull skiff will need some weight to be moved forward when powering into a head sea. Ballast isn't the ideal way to do this; if you foresee running lightly loaded on a regular basis, the ideal solution is to move your own body weight forward, either with a tiller extension or with a remote steering console. (A remote console also has the advantage of making it possible to have a full-height transom or motor well, either of which is a huge improvement in safety over the deep transom cutout needed to fit a small outboard.) Small boats of any kind are very sensitive to trim, as I'm sure you're aware, and it usually takes a bit of experimentation to figure out what works well for any particular boat.
     
  3. Gilbert
    Joined: Aug 2004
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    Location: Cathlamet, WA

    Gilbert Senior Member

    The FS 14 does look like a very nice boat.
    But as long as we are allowed to make shameless plugs I will attach an article about a great flat bottomed skiff that is a little bigger and so will be a little better for the weight carrying part of your requirements. It has more beam and so will have better stability. And the dimensions to loft and build your own are in the article. If someone chooses to build one using the stitch and glue method I can supply panel dimensions that my computer tells me are accurate but have not been used to actually build a boat.
    The pictures accompanying the article are not of one of the original boats but one that the moderator of the smallboatforum website built from the article. There is some discussion of the boat on that site and some accounts of trips he has taken with the boat with pictures in some. I would not advise a motor well on this skiff if you would like to use as small a motor as will be satisfactory for your use. I recommend 15 horsepower. But some folks might be happy with ten. Personally, I would not put a platform in the bow of this skiff as it gets in the way of stepping in and out of the bow which is one of its most endearing features in my opinion. But a platform will keep some gear out of the rain. It's always tradeoffs, isn't it.
    One small footnote, this is not a Pacific City dory even though it has a very strong resemblance to those boats. I am not offended that folks refer to them as such because those are fine boats too. It is just not quite accurate.
     

    Attached Files:

  4. Tapio Peltonen
    Joined: Aug 2009
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    Location: Turku, Finland

    Tapio Peltonen Junior Member

    Thank you for your suggestions. I think I'm still going to build the FS14, but I realize there are some definite benefits to the flat bottomed designs. Maybe I'll build one of those later.

    I'm going to build a tiller steered version because I think a center console would take up too much space. I'm just going to have to steer from the center bench with a tiller extension when I'm riding the boat alone.
     

  5. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    A tiller extension is very easy to make and will greatly improve the trim (and thus handling) characteristics of most small outboard powerboats when running solo.

    I would strongly encourage you to consider either mounting the outboard on a bracket (leaving the transom full-height) or building a small, full-transom-height motor well just ahead of the cut-down transom. I would argue that the single biggest risk factor in the design of a small outboard boat is the cut-down transom, over which waves can easily break. A full-height transom or a motor well goes a long way towards making a safer boat that you can have confidence in.
     
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