4 star for sure
I stayed at the sheraton marina for 3 nights in march 2012. This was my second stay at the hotel. This time I was given a standard room at the marina tower which is part of the main building. 
The hotel is a typical starwood 4 star property. It has a nice view of the marina and a starbucks located in the hotel. Check in and check out was quite smooth. 
One thing I particularly did not like was that the hotel charges a parking fee for guests. Although this is quite standard in california, it would make sense to waive this considering the hotel location. 
The breakfast is not the best in town but ok for a business hotel.