While Art Prize is happening, Grand Haven hosts a local art event where local artists have their artwork on display: http://www.ghartwalk.com/. It is similar to art prize where public vote on art displayed in shops and public places. There are also 10 Indy bands playing Fri and Sat night.
On Sat between noon and 5 there is a painted lighthouse competition where artists decorate them for judging by the public. Winner announcement is at 5 with bands starting to play at 6.
Lets meetup at the entrance of the piano factory building next to Porto Bello restaurant. We'll walk down Washington street to admire the light houses. Options afterward would be to get the sunset at the pier (7:30) or hang around for the music.