Lightweight Working Polliwog
We are day sailors and weekenders on a Bristol 27 sailboat. I don't think we will be shellbacks at any time in the near future (a Polliwog having sailed across the equator, and shellback having not). We sail off of a mooring pin, therefore, find that we need passage to and from shore. In my first attempt at building a yacht tender, I made a 7 foot pram out of quarter inch construction grade plywood. My 'beauty' weighed in at about 80 lbs. Being of somewhat slight physique (think Kermit the frog arms), I was having a difficult time getting my pram onto the top of the car. Looking around, I found that the design of the Polliwog made sense as a replacement in a number of ways: It had a pointed bow, that might make the boat fit on the foredeck of my sailboat better than a pram bow. It had a longitudinal rowing bench, making balancing rowing position changes possible. And, finally, it just looked more 'shippy'.
For this effort, I wanted to push the limits of lightweight, with the intention of still being able to use-and-abuse her (lovingly). By stepping up to marine grade okoume, I saved a bunch of weight compared to pine plywood. I also reduced the thickness of the hull from ¼ inch, specified in the plans, to 4 mm. I sheathed just the bottom, and over the chines with 6 oz woven glass. I didn't sheath the topsides, or the inside, to save some more weight. The transom, and seat support bulkhead, forward seat divider, and skeg where all laminated double thickness of the 3mm ply. The rest of the front seat supports and rear seat support were single layers. The corner knees, and seat tops where all single layer ply rather than solid wood. I put a small solid wood strip on the edges of the exposed ply for cosmetic reasons. In order to prevent damage to the mother ship, I put (well) used fire hose over foam pipe insulation around the gunnel for a fender. I'm guessing the pipe insulation material will get squished, and will need replacing every few years. I screwed a small sacrificial aluminum strip from stem to stern on the skeg for protection. For additional thickness in this area, I extended the skeg all the way up onto the prow. This also makes the aluminum strip stand proud of the hull, helping to protect her when dragging out of the water. Because I did not want to show off my less than perfectly smooth hull (it is a working boat after all!), I painted it white, with a thin cove strip for visual interest.
My new creation weighs in at about 45 lbs. with everything attached. I have no trouble getting her on top of the car by myself. With my wife helping, it is almost effortless. I have found that the Polliwog rows well. Before mounting the oar lock sockets, I took a trip down to my local lake with oar lock sockets in hand and a couple clamps, and got in the boat. I positioned myself in the boat so there was as much skeg in the water as possible without the transom dragging, and marked the spot for the oar lock sockets. I then did the same, with my wife in the stern seat. Turns out, it balances well with me almost snug into the bow of the boat, which provides the whole area between the two of us for cargo.
We plan on being a little more careful with our lightweight Polliwog about avoiding rocks going ashore, and with throwing heavy things down from the mother ship. I suspect she will give us many good years of service.
Gordon