Grand Union Paddington Arm Visitor Moorings

Hi,
We are two 58 ft boats making for Little Venice about mid May.
We are trying to find out if visitor moorings along this stretch of the
cut are are easily available or are we able to book ahead ?
The guides we have are either incorrect or vague enough to make us
enquire.
Any data much appreciated.
Thanks, Peely...

Thanks both for the nuggets of information.
We are currently at Marsworth having a day off and letting the
weekenders do their thing.
I guess it will be 7 days or so before we get there.