I'd used the Davies' boatyard previously. Parking isn't that much of a problem, you just stick it in any nukes and crannies you can find, between parked boats and I learnt to block the trailer off with the car, ie, unhitch the trailer, easier to park.
Only problem is the slip is very STEEP, ( now I know why there's a manual winch on the side). On the plus side, the plontoon is excellent for loading and unloading, not to mention it's a lot cheaper than Cobbs.