A lot depends on how fast you motor.
Figure on going 1 to 1.5kts slower on average but under the blue water
bridge, expect to open her up full throttle and crawl ahead. We found hugging the Canadian side was best to avoid the current
but for about a 1/2 mile, we were doing 1.5kts over ground at full throttle.
If you are concerned about making it in a single
day, the city of St. Clair has a nice marina you can pull into to split the trip in half.