There is the Alilaguna water boat service that goes directly from the airport to the Zattere Ferry Terminal. Your hotel is located very close to the terminal. Alilaguna has four lines, and you will want the Blue Line. Your stop is the next stop after San Marco. Keep in mind that no matter how you make the trip it’s going to take at least an hour or longer. Boats leave every 30 minutes, so depending on your arrival time you may have to wait a few minutes for the next boat.
Another option would be to take the bus or a taxi from Marco Polo to Piazzale Roma. From there you can hop on the Vaporetto and get off at the same Zattere Terminal. There are many Vaporetto lines that stop at Zattere including 2, 5.1, 5.2, 6, 8, 10, and 16.
Taking the Alilaguna eliminates the transfer from bus/taxi to Vaporetto and allows for a hopefully scenic trip across the lagoon should the weather be nice. Many of the Vaporetto lines go down the Grand Canal, so that might be a nice way to enter Venice, again assuming the weather is okay, and the boats are not too crowded. But, you have to transfer from land to water, which means some waiting time potentially at Piazzale Roma. The cost is pretty close with either option, and both will take at least an hour. Most people will utilize one of these two options. You could hire a private water taxi, but they are very expensive, especially for a group of four.