Comments on: Surprising speed difference 12ft Oz Goose vs 8ft OzRacer

By: Michael Storer

Michael Storer — Sat, 04 Apr 2020 06:38:31 +0000

In reply to Ben Tucker. Judging by performance difference is it over some sort of hump. D/L is a very crude measure. Further increases may not show the same benefit and start hurting in the Sail area to wetted surface.

By: Ben Tucker

Ben Tucker — Sat, 04 Apr 2020 04:36:37 +0000

Interesting read. Thanks. It would be interesting to run the disp/length figures. And the D/L limited speeds. I wonder how a 16 foot version would go?

By: Michael Storer

Michael Storer — Fri, 03 Apr 2020 00:10:38 +0000

In reply to Johan.

Thanks Johan.

Should be 2014/15. I fixed the typo.

Very grateful
Michael Storer

By: Johan

Johan — Thu, 02 Apr 2020 07:42:12 +0000

Oz Goose designed 2008, Ian Henehan’s videos 2004 ?

By: Michael Storer

Michael Storer — Mon, 02 Sep 2019 09:53:57 +0000

In reply to Michael.

Hi Michael.

From the water’s point of view it sees no difference between the planing boards as you describe and a transom.

In general the thing we want there is a sharp edged corner. So we don’t usually glass tape along the edge of the transom.

As long as it is reasonably sharp the water will go straight. If it is rounded the water will go around the corner and make a little wave at the back of the boat implying energy lost from making the boat go forward.

So no difference.

There is a risk though. The overhang of the planing boards becomes a very easily damaged edge as it is a continuation of the bottom ply. And it adds a bit of fiddling to the building process.

So in the end … if the bottom and side edges of the transom are reasonably sharp, the planing boards are redundant.

Best wishes
MIK

By: Michael

Michael — Sun, 01 Sep 2019 15:37:22 +0000

Has anyone tried shifting the transom forward an inch or so to allow the bottom hull panel to extend slightly past the transom? I wonder if this would help the boat plane (and hold the plane) a little easier by creating a sharp exit of the water surface tension as opposed to the 90 degree angle of the transom.