Here is a youtube video of a competitive team race start and a complete 200m race.
In the lower left you can see the boat speed in kilometers per hour. You can see they peak at 20 KM/HR and average about 17 KM/HR.
We are nowhere near that fast yet...
If you have time and are interested you may find these videos helpful.
This techniques video from the Camden Haven Dragon Boats club in Australia has some great footage the boat.
Their approach to paddling is very similar to what Jo has been teaching us.