In centuries past, Venice had a royal vessel known as the "Bucintoro". This vessel was as dear to the Venetians as the Statue of Liberty is to Americans.
Unfortunately the Bucintoro was destroyed when Napoleon conquered Venice.
To date there have been several movements interested in rebuilding her, but thus far none have accomplished their goal.
According to Nereo Zane:
"In modern versions of the Regata Storica, the Bucintoro is replaced by this boat, known as the Serenissima."
It can be confusing because a number of boats are painted on similar themes. A similar vessel carries Venice's iconic winged "Lion of St. Mark".
Here's another look at that boat:
And a great close-up of the sword-weilding lion:
A distinguished gentleman dressed as the Doge waves to the crowd from a third boat. I've never met a real Doge, but that guy sure has the look, doesn't he?