The voice of Boris - rapidly becoming the voice of doom - gave plentiful warning - the trip to the Olympic Park would be no cake walk.
Instead, expect jams, delays, armpits, fluster and confusion, he said. It might not have worked out quite like that (thus far) and the alarm, apparently, had its proper effect.
Water Chariots is riding the wave of congestion phobia with its unhurried, 40-minute, VIP jaunt up from Limehouse (or down from Tottenham Hale) to a private entrance direct to the park. Pre-bookings were healthy when I visited pre-Games.
For a ticket, £95 offers the VIP package, £45 for a slimmed down version and many thousands to hire out one of the smaller boats, aimed at corporate customers looking for a bespoke service.
A bit steep was the first reaction - "ridiculous" was the verdict of MP Jim Fitzpatrick - but the operator says this is not a water bus, it is an experience.
Founder Peter Coleman said: "Every day we hear about the potential for delays, disruption and unprecedented congestion. If you have paid for a once-in-a-lifetime experience why not take a stress-free, reliable and uncongested journey straight to the park."
Speaking before the Games and referring to the high end packages, CEO Bill Doughty, pictured, said: "Imagine you're in charge of corporate hospitality. Your worst fear is that you've taken two tables of 10 in a prestige suite.
"These are your nine best clients and you're looking at the two empty spaces at the table and you're thinking 'where are they' and someone rings up and says 'I'm stuck in Stratford in a queue at the station' or 'the DLR has broken and it's all gone wrong'. The stress is incredible.
"You just want the security of getting there and arriving."
Besides, this is no fly-by-night, here-today-gone-tomorrow operation, he said.
Water Chariots is part of the legacy with a contract to run the service for 15 years and with a self-imposed commitment to train up injured ex-servicemen. This was the dream of Mr Coleman whose son had done tours in Afghanistan and who is now working with veteran charities to make it a reality.
I took a preview trip to the Park in rare sunshine, up to the park on one of 17 smaller boats, which cater for 10, and back down on one of the 13 large boats, which take 70. It cost £3million to bring the fleet together.
The water is only three feet deep in most places so no cumbersome lifejackets are required ("stand up" would be the advice to the man overboard) and the sights of east London from the water are invigorating and informative.
From the delightfully named Bow Locks, the cottage where Zig and Zag ruled The Big Breakfast, the first glimpse of the Orbit, the old evocative warehouses with broken windows and fluorescent graffiti, the new converted warehouses, their balconies filled with pot plants.
Three Mills, where Danny Boyle was masterminding the celebrated Opening and Closing ceremonies and the eclectic gathering of riverside buildings. Tanks and armoured vehicles, we were assured, are just props from the studios but the soldiers pedalling the towpaths or under camouflage are unnervingly real.
On the tour, Mr Doughty told me the story. He said: "Originally, it was born out of an idea by Peter Coleman who is a passionate boaty type but has never been involved in any commercial boat operations.
"Two years after the Olympics were announced, he said to the ODA 'you've done nothing with the canals' and it said 'that's a good idea'. British Waterways said it would do a public tender to run a canal service exclusively down to the Olympic Park using the River Lea.
"He tendered. His was a whole romantic notion and he won. He played around with it for a bit - a nice idea, maybe a few boats, all very interesting.
"He didn't realise how interested people were, particularly event companies thinking 'we've got a completely unique experience now'.
"My background is in private equity and I have a philanthropic investment boutique that I run as well. I said if it's a partnership with British Waterways and if you can make 15 year legacy deal then I'm interested - I'll raise the money for you, I'll get you the boats, I'll do all of that, build you a team and bring the operation to life."
Expect it to be a hit. Especially in the second week once the horror stories of the first have filtered through and panic measures are deployed.
Go to water-chariots.co.uk
