From Venice, take a quick boat trip to Lido, and enjoy a two pedal bicycle.  Really fun!  Make sure you don't drive on the opposite side of the road like some people would do.  It only costs few euros!

Water buses run frequently over the lagoon to S. Maria Elisabetta landing stage.  The No 1 water bus runs the length of the Grand Canal from Piazzale Roma , calling at all the landing stages on the way, before  finally reaching Santa Maria Elizabetta landing stage on the Lido  and taking around 58 minutes over the journey.  The quicker 51/52 water bus line circumnavigates the outer landing stages on Venice, both clockwise and anti-clockwise,  before going over to Santa Maria Elisabetta.  The anti-clockwise 51 runs along the Giudecca Canal and takes around 44 minutes for the journey.  The clockwise 52 water bus goes down the Canneregio Canal and along the northern shore of Venice before crossing over to the Lido  and takes around 48 minutes for the journey.  Single water bus tickets cost 6.50 euros and are valid for 60 minutes. but period passes for 12, 24, 36, 47 and 72 hours are available from all ACTV ticket offices at economical rates.

Make sure you walk straight across the peninsular to the beaches which are spectacular if only in size and surprisingly uncrowded during the week in summer.  It is a fairly short walk to the beach, of about 800 metres down the main road, Gran Viale S. Maria Elisabetta, from Piazzale S. Maria Elisabetta where you get off the water bus.

Have a meal while you're there.  There are restaurants near the water bus stop and prices are reasonable.

Remember that if you've got the Venice card or the ACTV period pass, it covers the ACTV land buses on the Lido, as well as all the ACTV water buses in the Lagoon.