In 1886, Commodore Ralph Munroe had built to his own design, the 28ft Double-ended Sharpie Lifeboat, Egret. For decades Egret has fascinated me, and I cannot escape the spell cast by Munroes lines; lines which show an uncanny resemblance to the distribution of volume in an Australian Surfboat.  This last point is worthy of note when one considers Egrets legendary reputation as a bar-crosser.

Egret was produced to perform the duties of mail boat, ambulance, supply boat and ferry for the early residents of the Biscayne Bay area, prior to the building of satisfactory road and rail links. I think that these people were mainly well-to-do winter visitors to whom the availability of a reliable, all-weather means of communication was of extreme importance.

The story of Egret is well known, and her exploits and abilities are legendary. Anyone interested in learning more should read The Commodores Story by Munroe and Gilpin, The Sharpie Book by Ruel Parker and various articles from the pages of Woodenboat magazine.

I have recently built two Green Island 15s  from plans drawn by Brisbane designer, Mike Roberts. Prior to commencing work on the first hull, I was struck by the amazing similarity between the body plans of the GI 15 and Egret. In conversation with Mike, it became apparent that he did not have any prior knowledge of Munroes Egret, and that I was faced with a classic case of, Convergent Evolution.

Mike Roberts is a designer who approaches most things from first principles, relying on physics and engineering to provide design solutions and proofs. I was already aware that the GI 15 was a fast boat and an easily built boat, but I was now becoming increasingly interested in her from an overall viewpoint.

 At my request, Mike superimposed the body plan of the Green Island 23 (GI15 proportionally enlarged to 23 feet) over the body plan of Egret. As I predicted, the similarity was remarkable.

Not long afterwards, I found myself sailing Mikes own G I 15 on a blustery day of winter westerlies, when the steady wind was over 25 knots and the measured gusts exceeded 30 knots. As most people know, there is a lot of water in Moreton Bay, but it is spread out thinly! Therefore, we had an ideal opportunity to test the boats ability to handle a steep, high chop in heavy conditions. Surprisingly, she does not pound in the manner normally associated with flat-bottomed boats this is due to her fine entry angle (19.5 degrees) and her generous rocker.

We were sailing the G I 15 under full sail on a day when at least one deep reef would have been appropriate this was done deliberately for testing purposes, and the 75kg of internal ballast (water ballast tanks plus solid ballast) proved its worth. The boats motion was unusually progressive and deliberate for a dinghy. Deeply flared topside panels provide plenty of reserve buoyancy, and ensure that the weight of crewmembers sitting to windward is generating maximum righting moment.

Flared topsides also contribute to the relatively narrow waterline-breadth and fine entry angle features which produce an easily driven hull under sail, oars or outboard motor.

The Green Island 15 did not capsize that day, despite the trying conditions. However, on a following occasion, Mike deliberately capsized her in the Noosa River for testing purposes. Unlike most sailing dinghies, she is not only self-rescuing, but self-righting! After re-boarding, Mike used a bucket to fill the boat until the water level inside was above the flooded waterline, then sailed the flooded boat for over a kilometer to the boat ramp!

In response to client requests, Mike Roberts has expanded the Green Island series to include 15,17.5, 18, 19.5, 21 and 23 foot examples, as well as the round-bilged Evolution series in similar lengths.

There has been an unfortunate prejudice against flat-bottomed boats, brought about by one of their principal virtues they are easily built, and therefore many bad examples of the breed are produced from inadequate plans. The existence of such boats as Egret, the Banks Dory, Thames Barge, New Haven Sharpie, Swampscott Dory, Flat Iron Skiff, Norwalk Island Sharpie, prove that with knowledgeable design and/or construction, flat-bottomed boats of superior performance are routinely produced. The Green Island 15 and her sisters add to the pedigree.

Although I may never get the opportunity to own an Egret, I will build a boat from the Green Island series. When I get to sail her, I suspect that the spirit of Ralph Munroe will be on-board, and happy.