Big Portage Lake Dive Map from Huron Scuba, Ann Arbor Michigan
Big Portage Lake near Grass Lake, MI
Distance: ~30 miles West of Ann Arbor
Depths: You can find depth (up to 40-45 ft) straight towards the county park beach on the other side of the lake.

Or, follow the shore south (to the right) to go past the day use beach and beyond to depths of 20-30 ft and a thick weed line.
Details: This large, multi-sports, public access lake is in the Waterloo Recreation Area, off I-94 between Chelsea and Jackson. It's about a 30 minute drive from Ann Arbor. There are three public entries: a county park (long swim to any depth), the Waterloo boat launch, and the Waterloo day use area, which has newly renovated bathrooms that are open during regular summer hours.
  • Take I-94 west from Ann Arbor towards Jackson.
  • Take Exit 150 (Grass Lake) and turn right (north).
  • Go about 2-1/4 miles and turn left at the first stop sign onto Seymour.
  • Drive about 1-1/2 miles, PAST Portage Lake Road, and look for the Waterloo Recreation Area / Portage Lake park entrance on your right.
  • Turn in here, drive past the entry building (currently under construction) and on about 100 yards.
  • Bear left at the fork to go to the boat launch, or right to go to the day use area.
More Information:


Huron Scuba, Snorkel & Adventure Travel Inc. 4816 Jackson Road Suite D, Ann Arbor, MI 48103 
Phone: 734-994-3483 Fax: 734-994-1597 Apply to join Huron Scuba's staff! Application form in PDF
Regular Store Hours: Monday-Friday 10am-7pm, Saturday 10am-5pm.