Venice Kayak will for a while–for practical reasons–do the tours from the island of Certosa, which is just east of Venice city.
The island is reachable by vaporetto 41, which passes the S.Lucia station (departure at 9:15 for arrival at the Certosa at 10am), Piazzale Roma (9:18), S.Marta (9:24); and on the Giudecca island: Sacca Fisola (9:28), Palanca (9:31), Redentore (9:34), Zitelle (9:37); and S.Zaccaria (9:41), Arsenale (9:44), Giardini (9:47), Sant’Elena (9:50); with arrival at the Certosa at 9:56.
By vaporetto 42, from Murano Museo (9:23), Murano Navagero (9:26), Murano Faro (9:29), Murano Colonna (9:32); then Fondamente Nove (9:41), Ospedale (9:43), Celestia (9:45), Bacini (9:48), San Pietro di Castello (9:55); with arrival at the Certosa at 9:58.
The Certosa stop is by request only, so tell the sailor on board that you need to get off on the Certosa island, when boarding the vaporetto.
Both vaporettos run a 20 minute schedule, so the previous vaporetto is 20 minute before the times mentioned above.
There’s a hotel on the Certosa island, and the meeting point is at the bar there, so the ones coming early can have a coffee and a snack.