jeff since you're from NY... maybe a little more info will help you there are many marinas on the delta near walnut creek just a half hour or so away...lazy m, orwood, discovery bay...if you've never been out on the delta you are in for a treat
Or you could head up to berryessa, its a lot easier to navigate, but during the weekend I wouldn't reccomend it...oh yeah,its about 1.5 hours from Walnut Creek