By COLIN MOORE
There is a difference of about three and a-half hours in the ebb and flow of the tide on the shorelines of Auckland's twin harbours.
Every now and again the incoming and outgoing tide on the Waitemata Harbour and Manukau Harbour falls in a happy juxtaposition that makes possible an adventure that is peculiar to metropolitan Auckland.
On the right day you can jump in a sea kayak and circumnavigate New Zealand's largest city, using two short portages that Maori used to haul their canoes across the isthmus on which the city is built.
On May 9, 1992, a small group of eccentric paddlers completed the first 59km circumnavigation of the City of Sails in a day. This coming weekend the voyage is to be repeated, over two days, as an organised public event. Up to 100 kayaks may take part.
The first circumnavigation of the city by sea kayak was the brainchild of veteran sea kayaker Ron Augustin, designer and builder of the Sea Bear sea kayak.
On that voyage we left St Heliers beach at 6.20 am and paddled up the harbour with the incoming tide, reaching the harbour bridge at 7.50 am with the sun beginning to appear behind Rangitoto.
From the bridge our pod of kayaks negotiated Meola reef and entered the Whau River. With the tide still with us we followed the waterway until it became a narrow creek behind the Avondale Racecourse, blocked by a sewer pipe and rail line.
Maori canoeists almost certainly paddled a bit further upstream. In the 19th century just 1600m separated Whau Creek from Green Bay and an enthusiastic Waitemata-Manukau Canal Syndicate survey concluded: "Unquestionably nature has destined that at some time these rivers shall be the carriers of great commerce."
A report in 1887 by a Mr Blair of the Public Works Department was more cautious. "It seems evident that the work [a canal] is not likely to be taken in hand for some time", commented the Auckland Evening Star.
The canal was never built, so we followed the example of the Maori and portaged our canoes the 3.5km to Green Bay using wheeled trolleys.
Catching the tides is crucial, and we left Green Bay at noon with an incoming tide on the Manukau and a strong wind in our favour.
Just over an hour late, we ran out of water in the black and foul mud behind the old Westfield railway station. From here to the Tamaki River, and the waters of the Pacific Ocean - as stepped out in 1908 by J. E. Taylor, president of the Manukau-Tamaki Canal Promotion Association - is less than 1000m.
The Maori made extensive use of the narrow portage between the two harbours. They called it Tauomo. It was a bridge on a canoe highway from the Waikato to the North. And in the 1850s European settlers put a two-chain canal reserve across the isthmus to connect the Waitemata with the Manukau.
In 1860 Colonel Moule, RE, estimated it would cost £22,876 to dig a suitable canal through it. Blair estimated £550,000.
Undeterred, Taylor drilled holes across our portage route and concluded from the sand, shell and beach mud he brought up each time that the tide had once flowed through the Manukau-Tamaki isthmus.
He felt it would be possible to dredge right through the isthmus at one-third the cost of the rival Whau scheme and one-sixth that of bridging the Waitemata "which would not nearly be so useful as the waterway across the North Island."
Portage Rd remains as a reminder of such dreaming, although we took a slightly longer route with our trolleys to reach the convenience of a boat ramp on the Tamaki River.
And now, with the tide on the turn, we paddled 18km down river, around West Tamaki Head, landing at St Heliers Beach at 6 pm - around the city in a day.
This weekend's around-Auckland paddle and portage has been organised by Chris Gulley of the adventure tourism company Outdoor Discoveries, in cooperation with the Auckland Canoe Centre, Canvas City and Wilderness magazine.
It is a non-competitive social event, a refreshing change in these days of multi-sport madness - but for those who can't resist racing, the event includes three timed sections.
The event circles the city in the opposite direction to our inaugural paddle, leaving from Okahu Bay and paddling east alongside Tamaki Drive and up the Tamaki River with the incoming tide.
After portaging across Otahuhu the paddlers, moving in pods of 10, will use the outgoing tide on the Manukau to paddle to Green Bay, a paddling distance for the day of 31km - and an overnight stay at the Motu Moana Scout Camp.
On Sunday, after a night of socialising and entertainment, the paddlers will portage along New Lynn's Portage Rd to the Whau River, and paddle with the outgoing tide 21km down the Waitemata Harbour to Okahu Bay.
Gulley says it has been a monumental event to organise, involving two city councils, a regional council, harbourmaster, coastguard and two traffic-policing units, as well as the event itself.
The event includes a Saturday night meal, a Sunday breakfast and spot prizes. It will also raise funds for the Auckland Coastguard and Surf Life Saving Northern Region.
Gulley expects about 70 paddlers. Late entries are accepted with a small surcharge.
The cost for a single kayak using a tent site is $135, and $220 for a double kayak. Indoor accommodation is available for a single at $150 and $260 for a double.
Entry forms are available at Canvas City, Hobson St and the Auckland Canoe Centre, Sandringham. They are also available on the internet at NZ Kayak or from Outdoor Discoveries, ph (09) 813 3369, e-mail firstname.lastname@example.org.
By COLIN MOORE