Bolger Bantam Modifications
By Tom David - Nantucket Island, Massachusetts - USA

Phil Bolger first designed the powered trimaran layout for what would become the Bantam for a client who wanted to recreate a river voyage in a sneakbox.

That project never got going, but later Bolger redid the idea for a Dutch couple with a wish list that Phil thought fit the Bantam: a light stable economical overnighter that would tow easily, fit in a garage, and handle a chop. He called it the Bantam 16-20. The bow would come off and stow in the boat for trailering or garaging, and the cabin top would lower to the hull.

That boat never got going either. Here is the drawing from June 1999 MAIB:

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I started the Bantam in February of 2001. It was the first one built, and served as a kind of proof of concept for the design. Here is Bantam 5 years later on the Erie Canal...

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For those readers considering building a Bantam, I'll just list the changes I've made. My wife considers it "perfect", and so do I.

  • Deck more of the pontoon bows for storage/ seating. The anchor stores in a laundry basket under one deck, and a spare 3-gallon tank under the other. The suggestion to store the anchor in the detachable bow section was impractical.
  • Use four 3/4" bolts to attach the bow piece instead mating blocks as in the plans.
  • Widen the stern pontoon decks to allow under storage for two 6-gallon tanks on one side, and spare anchor/storage in the other. There is additional storage under the shelves that hold the tanks.
  • Build low extensions on the pontoons to add length and make boarding easy. When the boat was first in the water, it was down at the stern, so I bolted extensions on to help it float a little higher. I later made these extensions permanent.
  • Add 4" of foam and ply to the pontoon bottoms, and 1" to the hull, and add 4' of 1/4" ply doubler on battens to the bow sections between the pontoons. The boat needed to sit higher, and resist a wave impact to the bridge.
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  • Close the stern off and extend the motor mount. The boat handles better, is quieter, and now there is a new rear deck. The engine controls run under raised cedar decking, and the steering cable runs just above the decking.
  • Make the windows and steering station removable instead of hinged. The windows store on the floor when the boat is moored or on the trailer. This is a lighter arrangement, and simpler.
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  • Substitute the lighter and more reliable Honda 15HP for the 25HP Mercury four stroke. Making the boat as light as possible is the key to efficiency.
  • Make the cabin roof lighter. The method and details of raising and lowering the roof was the toughest problem. It now takes only a few minutes to close the roof down and make Bantam secure on her mooring, with a lower wind profile and better security from mischief. The aluminum hoisting poles store along the transom when not being used. Here is a photo of part of the three step roof raising/ lowering, a one-person job.
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  • Change the plexiglass side, bow and stern windows to lighter clear vinyl. The vinyl stores in the pontoons most of the time, or stays up when making a longer trip in cool weather.
  • Move the galley/storage to the forward end of the cabin.
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The Bantam tows on a double PWC trailer modified with a slide up the center.

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We spent 12 days and nights on Bantam for our trip. The 15 HP Honda with remote and power tilt gave a top speed of 12 knots, and we cruised at 8 to 10 with very little engine or hull noise, using around 3/4 gallon per hour. Total trailer weight ready to launch is 1800 lbs.

The only future modification planned is a new steering seat outside the cabin that swings to different positions and is removable. Part of the enjoyment of cruising on Bantam is the ability to change your position when steering. You can use the inside seat, stand, or rest against the galley top. The new exterior seat will mean you can stretch your legs out outside the cabin while steering with your right arm on the wheel.

My wife and I just got back from a 670 mile 12 day trip on the Erie Canal, and had a wonderful time, almost totaly due to the to the pleasure it was to be on the boat. We ate every meal but one aboard, slept aboard every night, and cruised 8 to 12 hours a day, and were not ready to quit when it was over.

My wife and I are planning another two-week trip next year. It is impossible to describe what pleasure the design gives. Our thanks to Phil and Suzanne. For anyone considering building a Bantam, plans are from Phil Bolger and Friends, PO Box 1209, Gloucester, MA 01930, Fax is 978-282-1349.

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Tom David

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