I'm no expert on the lake at all but what I seen told and hear, is that Oswego and West are the spring and summer fisheries for salmon. Maybe it's a collation with deep water and current flows.
Seasonal lake and charter anglers I know are in Fairhaven, sodus and Oswego.
Oswego is fishing well from the guy I know charters on the Hudson river. All species are being caught pretty much daily.
I do know Mexico bay/ port Ontario comes into play big time in late July.
I would run to the red brick over at Oswego often and troll out =NW but it's a good 8-12 mile haul just to start setting gear. Try that in 4-6 footers, BTDT.
So to answer the question,
Personally I think it's deep winter over water with bait in close proximity.
Not saying no bait in Mexico, it's just a very big flat bottom bay for about 4 miles out , then it only drops about 100 more feet, total 225 ish for quite awhile. We been swimming in 400 fow and made it to 600 a few times.
#1 thing is if you venture out , make sure the vhf works !
Second is a GPS.