My advice ( been using Christchurch lots over the years) ...BIN IT.
Its strong strong easterly winds - which will make it miserable . Its forecast heavy rain Sat - so crappy viz to compound strong winds...
Stay in / go to the PUB - but don't take a 3m out unless its a YBoat and you've got drysuits ......
You wont get the chance to worry about running aground - I reckon you'll be too worried about staying alive and getting home OK ....
Poole can be equally crappy in Easterlies - I don't fish so have no idea as to spots , but given the wind strength I'd plan weekend at home