SwimJim:The reason I suggested Munising is that there are easily done shore dives for the inexperienced. These are Free by the way. The local charter boats offer and option to go to wrecks as deep as 90 fow and that might scare off newbies. BUT, they also offer trips to wrecks like the Manhatten and the Herman Hettler.
Jim
One thing you're not considering is drive time though. It's a 9 hour drive to Munising for me and 1:45 to Gilboa. The Chicago folks are looking at a 7 hour drive to Munising and 4:15 or so to Gilboa, our Cincinnati contingent is looking at a 10 hour drive to Munising and about 3 hours to Gilboa. Munising would be a great place for the Michigan and Ontario people to meet but it simply isn't central for everyone. We could do Lake Erie but the vis was horrible when I dove it in May, I don't know what it's like in April but I was told to dive it in late summer to get the good vis.
This is our kick-off to the dive season, many haven't been diving all winter and use the quarry to "get the cobwebs off" before hitting the lakes. The quarries are a convenient practice ground and they let you keep your skills fresh when you can only get away for a day rather than the 3+ days for a trip to a destination that's farther away. Just food for thought.
BTW, I think anything in April is good for me, I start diving with the advanced class in May so those weekends are booked.
Ber :lilbunny: