Bay seniors whose idea of summer lolling runs about 2 mph are invited to check out the Lafayette Reservoir a few miles past the Caldecott Tunnel. Among its pleasures are rental pedal boats as well as rowboats and kayaks. Boat fees are $15 an hour with a $40 refundable deposit. You can fish off their pier and get your gear at a small shop nearby. 125 picnic tables dot the shores and there is a 2.7 mile easy, rolling paved path. Dogs allowed. $7 all-day parking fee. Weekends get crowded early. And of course when the temperature rises in the summer, it can be scorching out here in Contra Costa. Sadly, no swimming. If you want to splash around try Lake Temescal a few miles west off Hwy 24.