Waves can vary from gentle rollers to 30' tall monsters. It all depends on the direction and speed of the winds.
I would hazard a guess that 80% of the surf fishing in the great lakes is done by plunking spawn or tossing harware.
Most of the river mouths (bigger more popular rivers) have a peir or harbor. This prevents one from truly fishing the mouth. People then fish the flume or river water flowing out into the lake.
Winds then really affect the way it goes out into the lake, sometimes hugging the shorline other times it will flow straight out into the lake.
You can also fish the lessor known streams and creeks, which will offer true river mouth access. They are a real hit and miss affair since they were rarely if ever stocked and rely heavily on H2O from the sky to draw the fish.
Some surf fishing is done at the mouths of warm water discharges or on a shoreline near deep drop offs. Most times it is a hit and miss affair, but if you hit it right you can experience some good fishing.
The spring smelt run is probably the best time to tangle with some hog fish stuffed full of smelt. I have caught browns stuffed full of smelt their stomachs bulging from the feeding frenzy. If you manage to hit the alewive spawn you can also rip into some nice fish.
They are some greedy fish when they put on the feed bag.
One thing of note is that the food chain bio-mass has been declining the last few years. this is a result of over stocking from the GL states. Lake Michigan has 4 states surronding it. Each one of those states pump tons of game fish into her. As of late the biologists realized the error and have reduced stocking levels to allow baitfish rebound. Couple that with the lake being way below normal levels (last I heard it was 5') makes one wonder how long the bounty will last. After all everything changes sometimes it is not for the better.