Depends on the dives. Mainly I do Great Lakes so anywhere from 45 minutes to 90. Depends on deco time I want to do.Couple of questions..
What’s your typical runtimes? 60mins, 90mins, 120mins?
Is it normal to ascend on the shot line or do you bag off (send up a SMB) from the wreck?
Typical depths?
What’s the current like?
Water temps are anywhere from 38 F to 45 F. That dictates a lot of the run times on the lakes. Especially on OC. Longest I have done is 105 with 66 of that being deco.
Most of the wrecks have buoys on or just off of them. So ascending on the line is common.
110-165ft.
Current can be non-existent to 1 knot. Even though they are freshwater there is a lot of water moving through the lakes and it can be deceptive. You can also get a lot of movement near/on the surface if the wind picks up at all. Since the boat is moored, coming up on a bag can result in a long swim or wait if the wind picks up.
Been out on flat calm days and days where 2-4 ft waves were running.
Anything over that the boats don't usually go out.
25 ft waves have been recorded on Erie during storms and they can come up quick.
On the larger lakes even bigger waves have been recorded. It has been estimated and modeled by NOAA than the waves that sank the Edmund Fitzgerald could have been as much as 46 feet.
I've also been out in the Pacific off Monterey and had to deal with a fair amount of surge and surfacing in a kelp forest.
Not deep less than 90ft but challenging.
My first dive in the Pacific was also my first saltwater rescue assist. As my buddy and I completed our kelp crawl to the boat we heard someone shouting for help. DM dove out over our heads and I followed him.
AOW diver who had never dived colder water (56F) was in 7mm for the first time. Lost his buddy and wore himself out trying to swim through the kelp. On the verge of panic but not quite there yet. DM and I got to him and had to tow him back to the boat.