July-August Ontario Diving

[Underwater Tourist]

Hello everybody,

Would anyone like to buddy up for some dives in late summer? I live in Toronto, but I never dove any of the local sites so I am open to go pretty much everywhere. Only restriction on my side is that I dive wet (5mm+3mm under suit), so for colder places like Toby I would like to go very late in the summer when the water gets above 20C (on a related note, how is the water temp at depth there?).

 

[davecampbell]

toby is cold, at depth, no matter when you go.

 

[Underwater Tourist]

I thought it warns up like lake ontario and st lawrence river.

Clearly not

 

[Ontwreckdiver]

Lake Ontario is cold at depth all the time. The St. Lawrence will get up to 68 to 70 F from top to bottom in the late summer and fall.

 

[Underwater Tourist]

What is the temperature in Toby at depth throughout the year (I assume it doesnt change much) ?
And same question for lake ontario?

 

[davecampbell]

I thought it warns up like lake ontario and st lawrence river.

Clearly not

it warms a little at the surface, but for example, the Niagara II is usually in the low 40s

What is the temperature in Toby at depth throughout the year (I assume it doesnt change much) ?
And same question for lake ontario?

40s

 

[PiratePrentice]

Regardless of water temp in Tobermory, I'd be happy to join. I'm located in the Guelph area.

 

[divingx]

If you only dive wet, my recommendation is to start with Brockville (St Lawrance), then Lake Ontario e.g. Kingston, and Tobermory at the end of the season.

Brockville / St Lawrance River is basically warm surface water from Lake Ontario. There's almost no thermocline at all for recreational depth. Many divers use only 5mm wetsuits.

Lake Ontario will warm up around late July / August. There will be some thermoclines. The first 18 meters / 60 feet could be really warm but murky. Then the temperature could drop to ~15℃. Below 30 meters / 100 feet will probably be below 10℃.

If you want ~20℃ in Tobermory, go there in September. All the shallower wrecks should have a water temp around 18-20℃. Even the shallow end of Niagara II could be 18℃. Obviously, it will be colder if you go deeper. But IIRC I got 14℃ on my computer at Forest City at maybe 45 meters / 150 feet in September last year. It's still in the wetsuit range but you probably need a 7+7.

 

[Underwater Tourist]

@divingx thank you, yeah I read around and figured I will be limited to lake ontario and st lawrence river

toby will be pushing it diving wet, doable, but not enjoyable

 

[p_kos]

Lake Ontario is cold at depth all the time. The St. Lawrence will get up to 68 to 70 F from top to bottom in the late summer and fall.

The St. Lawrence can actually can get to 75-78F in the summer. 3mm wetsuit water, no thermoclines.