For Lake Michigan deeper wrecks are always going to be ~38-40f (~4c) on the bottom. The plus side is the thermocline can be very nice in the summer. You can usually expect low 60s on deco / shallower depths. It's one of the reasons that I like the Arctics Expedition or Halo so much. It's sometimes a delicate balance of layering for the bottom temperature and not roasting on deco (although that last part is usually not a problem).
The big challenge is not overheating and sweating profusely in the heat of the summer as that is going to make you much colder on the bottom when everything is already drenched in sweat
I recommend getting all your dive gear/equipment sorted out first before putting on undergarments and zipping up into a drysuit. Your equipment should be assembled and ready.
It seems obvious but this is where I often see people struggle in thicker undergarments. By the time they get suited up they start working on some piece of gear or forget to do something and now they're assembling things in a drysuit for 40 degrees on the bottom and baking in 90 degree heat. They start feeling sick or dizzy, add in some waves and they start to get sea sick. Stay hydrated and if the boat you're diving from has an bimini top or shelter from sun, take advantage of that.
The big challenge is not overheating and sweating profusely in the heat of the summer as that is going to make you much colder on the bottom when everything is already drenched in sweat
I recommend getting all your dive gear/equipment sorted out first before putting on undergarments and zipping up into a drysuit. Your equipment should be assembled and ready.
It seems obvious but this is where I often see people struggle in thicker undergarments. By the time they get suited up they start working on some piece of gear or forget to do something and now they're assembling things in a drysuit for 40 degrees on the bottom and baking in 90 degree heat. They start feeling sick or dizzy, add in some waves and they start to get sea sick. Stay hydrated and if the boat you're diving from has an bimini top or shelter from sun, take advantage of that.
