My goodness, I just wrote a lengthy response, but I'm breaking in a new computer, and it is lost. I don't have time to rewrite it, as I already described it upthread anyway. There is a shared water taxi service, and you can find it hear. Venice Shuttle IN (Airport Link) Venicelink
It's going to cost about 38 euros for two people. That's the same as Alilaguna. Like Alilaguna, you are going to have to wait. The boat won't take off with two people. You might have to wait for 45 minutes for the plane with the last reserved passenger to land. Or, you could be the last ones. You could be the first passengers dropped off, or the last. In other words, the money is the same, and you might have to wait as long as Alilaguna.

There's really nothing wrong with Alilaguna. It takes longer than an hour, but at least if you get a good seat, there is scenery. It's not like JFK to Manhattan, and it's only half the price,

Put Alilaguna into perspective. Have you tried to go from JFK to Manhattan? It costs twice as much for a taxi cab, which takes twice as long, and there is no scenery. You are just stuck in traffic on the Belt Parkway. SFO and LAX aren't any different. VCE is a cool airport, super modern, comfortable, great food. You get on the Alilaguna and enjoy great scenery along the way at a very low price. The time, which is longer than 45 minutes, is going to be quicker than a shared water taxi. The shared water taxi is a new thing. How do I say this? (Scratching my head). Water taxis in Venice are very tightly regulated, like taxis in Rome. No crime or cheating. I won't refer to any movies by Brando, but let's say, these new services don't have a pure reputation, and are of strange provenance. They are 100% safe, but they don't shorten the ride because it's like a shuttle.