I'd like a direct boat to our hotel on the island.
You can take a Venice water taxi (basically a high speed boat). Water taxis from the airport are pricey (about 100 euro), but if you have a large group (they carry up to 9 people).
http://www.venicewatertaxi.it/?lang=en
There are plenty of water taxis at the dock at the airport (just a little walk from the main terminal). Not all hotels can however be reached by boat, therefore there might still be some amount of walking from the closest place where the taxi can take you to the hotel.
Another option is the Alilaguna boats.
http://www.alilaguna.it/en
They are cheaper but they drop you off only at predetermined spots.
It might be helpful if you were to either check the website for your hotel which likely will give transport info; or share the name of your hotel or its location here and we can give the best answer. Venice is made up of nearly two hundred islands. Which one?
How many in your party? All adults?