16' Apollo Vaka / 18' Prindle Ama Trimaran

Discussion in 'Multihulls' started by TriJody, Oct 4, 2015.

  1. TriJody
    Joined: Oct 2015
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Phoenix, AZ

    TriJody New Member

    My goal is to have a safe / seaworthy daysailing trimaran to use locally in Phoenix, Az; primarily on Tempe town lake which has a mast height restriction of 30'. I already have a 16' AMF / Alcort Apollo sloop and recently procured an 18' Prindle catamaran within the last couple of months. I've removed all hardware from both boats and test fit the apollo on the prindle trailer with the prindle hulls along side. They fit albeit without any room to spare. The deck height is equal as they sit on the trailer now which would be ideal for straight tubular akas. The keel of the prindle / amas is about 6-8' deeper; this is primarily why I'm asking for advice.

    I've noticed that there are many variations in hull configurations but primarily slender vakas, equal in length to the amas. The keel of the amas is usually more shallow than the main hull. My concept is far from the "standard" with the round "tub" shaped keel of the Apollo and the massive (in comparision to main hull) amas. My primary concern before I start fitting the akas, is the waterline and draft of the amas compared to the main hull. I certainly don't want the main hull to be completely suspeneded above the water. The hull wieght of the Apollo is ~300lbs, Prindle is <400lbs. The Prindle mast will be used but chopped about two feet at the top (the mast is damaged). I'd estimate the total wieght when completed to be ~850-950lbs. The akas will be made with 3" OD aluminum tubing and wiegh ~40lbs.

    I'd like everyone to tell me that it is fine in this config so the akas are easy to fit but if the amas need to have at a more similar keel depth I can raise them.

    Here is a reasonably acurate drawing of the Apollo / Prindle concept.

    The next diagram illustrates the keel difference at equal deck height

    I originally posted my project here:

    I was referred here.

    Attached Files:

  2. Doug Lord
    Joined: May 2009
    Posts: 16,679
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Welcome to the forum! I pretty much agree with what Greg said on the other forum. In the small sketch showing the boat folded, it appears to me that you have the flat side of the Prindle on the inboard side-it should be outboard.
    Ideally, the ama's on a sport tri should not touch the water when the boat is level or very little. That means the main hull has to support the weight of the amas and crossarms. I'm not sure that's possible with this combination. If both amas are substantially immersed to start with the boat won't handle well at all.
    Good Luck!
  3. TriJody
    Joined: Oct 2015
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Phoenix, AZ

    TriJody New Member

    Thanks for the advisement Doug. I appreciate you taking the time to do so.
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