Lake yard has visitor berths and the food is good.
Cobbs Quay yacht club the food is mediocre and hit and miss, upside is the beer is good.
Poole boat haven has visitor berths with several eateries in and around the quay.
Shell Bay Restaurant has a pontoon in the adjacent boatyard (owned by same peeps) but I believe it dries out at low water. When Veronica and I went earlier this summer (by foot) I asked if we could use the pontoon and the waitress said no probs. The food here is good and worth a visit.