Grand Haven

Well, you're no more than about a mile from Lake Michigan, which is a good place to swim - if the winds haven't changed and brought in cold water. I an actually out there a lot of weekends, and swim right in front of the beach. If it is a nice day, it will get pretty packed by mid to late morning, but you can easily beat the crowds there. There are some other good spots to swim in Grand Haven, too, if you want to avoid Lake Michigan, but I can't think of their names and would have to get back to you.

As far as biking, I would take a look at the Grand Haven Triathlon bike course. One note, you probably do not want to start at the transition area, because the roads around that will be very busy. I'd start about a mile from transition. If that doesn't look appealing, another place I will bike is in Spring Lake. Park at Spring Lake High School and bike east on Leonard. You can get in a good long bike going that direction.

Running options abound. I would run the boardwalk on the pier at least once. You can follow the sidewalk it is for quite a distance.