the various water busses take different routes so check before boarding - the blue line for example goes via Lido which takes a while
They don't stop at all the the stops the vaporetti (in town water bus) use - you might want to change in the city to a convenient vaporetto that lands you close to your hotel as lugging bags through the streets is a nightmare
Orange "A" goes down the Grand Canal - price is 14-16 euros one way and takes around 75 mins to the end of the line in San Marco
A water taxi has real style and takes 30-40 minutes to San Marco but it's around 100 euros - so it really is a matter of how many people and how much $$$ you want to spend
Visibility out of either is reduced by spray on the cross lagoon part of the trip but is good in the city area