Sunday, March 29, 2009

South to Wedding Cake Island

If there is one thing that Sydney kayaker's dream of it's an archipelago of islands lieing off our coast. This morning we sought out Sydney's single offshore island - more of an inshore reef really - as the half-way point in a paddle south from the Harbour.
In the pre-dawn darkness Tony's first few paddle strokes were interrupted by an Australian Salmon.

Post - Equinox dawn.

Autumn has brought with it the morning westerlies, allowing us to sail on a reaching tack up and down Sydney's coastline.
Luke (above) and Tony (below) taking advantage of the westerly winds tumbling over the cliffs and streaming out to sea.

Heading slightly east of south, out to sea, to fill the belly of our sails.

Just south of Bondi the morning westerly abated and the sea's calm surface revealed an enormous and ponderous jelly fish pulsating its way through the suspended microscopic creatures of the East Australian Current ...

When life forms are found outside of our solar system they may look something like this beautiful creature.
Tony positioning himself to catch a wave peeling across Wedding Cake's reef.

With a light sou-wester filling in we were able to set sails again and lean our shoulders into the breeze for the journey back up along the sandstone cliffs to the Harbour.

Today's path.

Sunday, March 22, 2009

The V-sail

Some thoughts on how the shape of the V-sail could be improved ...
How is the design of this sail different?

i. The top edge of the sail has a "swept profile" which I believe would better distribute the structural forces operating within the membrane of the sail to the masts, as compared to the current design which has a straight cut across the sail's top edge and concentrates the forces at the top of the sail into the corners.
As well as improving the engineering of the sail, this design change also gives the sail a more dynamic visual appearance.
As in nature, there is no such thing as a straight line, everything is composed of curves.

ii. The centre area of the sail is composed mostly of clear fabric to maximize the visibility through it.
When the sail is sheeted down to one side on a reaching tack the visibility through this sail is still optimised - unlike the current design which limits visibility during such a sail setting.

iii. All of the sail edges are composed of the opaque fabric and where the opaque fabric is seamed to the clear fabric this is done along a curve - again to give dynamic expression to the spread of membrane forces operating within the sail's surface.

This sketch describes how the view line is preserved throughout the various sail settings.

Sunday, March 15, 2009

Autumn jaunt

A very gentle dawn at the Heads as we paddled into Sydney's autumn season.

Stretching legs at Wash-Away Beach.
Tony, Peter M, Luke, Al, Peter K and Tim.
Derek later joined us at the next bay around.

Despite the murky water from recent rain we took our chances with the sharks and snorkelled at Crater Cove.

The sea temperature is now a pleasant 22 to 23 degrees.

With salt water flooding into the housing of the supposedly water-proof Olympus 1030 camera this blurry photo was the last to be retrieved from the card's damaged memory. The obvious lesson is that electrical equipment and water do not mix.

There are a number of driftwood shacks tucked up above this cove that we briefly explored by foot before paddling back across the harbour to our various home ports.

This morning's trip was a pleasant stroll across the harbour.