I don't think its illegal.... just bad form.
That being said the real issue is the definition of No Wake...
270-D:1 Definitions. – In this chapter:
VI. "Headway speed" means 6 miles per hour or the slowest speed that a boat can be operated and maintain steerage way.
VIII. "No wake area" means an area where a boat is to be operated only at headway speed.
Here is a link to the MP definition of No wake.
http://www.winnipesaukee.com/forums/...ad.php?t=10308