Ascent rates

[johndiver999]

OP stated they were having trouble making the correct ascent rate on their SMB dives. I offered a solution. If you want to wind yourself up the line from the bottom, knock yourself out. Maybe you can go that fast. I don't know and it doesn't affect me. I know I couldn't. Can you stop your ascent to switch gases? I guess, but you're violating the assumptions of your dive plan and adding to your deco obligation. My training was very strict on getting off the bottom quickly and hitting your stops as perfectly as possible.

Thanks for the explanation. How long does it take you to do a gas switch? Your training requires that gas switches be completed while actively ascending and are not done while stopped?

 

[kensuf]

We sometimes have wicked multi-level currents in the gulf stream. I like to shoot the smb 20'-30' below the first stop to be able to manage any issues that arise from dealing with a multi-knot shallower current. I've seen more than one person get caught and yanked shallower than their first stop. It's always fun when you see an smb going straight up above you, then get caught in a shallower current and the line starts bending towards a 45° angle, that's a good indicator that you're about to go for a ride.

 

[PfcAJ]

I use a 400’ reel with #36 line on it.

that bags gettin to the surface no prob.

gas switch takes a minute or less.

 

[Manatee Diver]

It's always fun when you see an smb going straight up above you, then get caught in a shallower current and the line starts bending towards a 45° angle, that's a good indicator that you're about to go for a ride.

It is fun as long as you know you have enough line. At 60 ft with a 150 ft spool and you wonder if you have enough line as you watch the thing payout in a 2 knot current.

 

[Gareth J]

It is fun as long as you know you have enough line. At 60 ft with a 150 ft spool and you wonder if you have enough line as you watch the thing payout in a 2 knot current.

Great example I have.
Sent off a DSMB on the lee side of the Tabarka in Scapa. The DSMB went straight up, once out of the shelter of the wreck turned at right angles and disappeared out of sight.
I saw the centre of the spool appear on my small 50m reel, reached over and grabbed my buddies shoulder strap (just as she was about to slap me), I took off doing a superman impression, towing her behind me.
Once out of the shelter of the wreck, everything slowed down, and I had to reel 42m of line back in whilst we started our stop.

 

[KenGordon]

We were lucky enough to be able to spend a week in Scapa (N Scotland) last week.

Mixed group of oc and ccr depths from 25-45m 2 deco dives per day on average and either ascent via the shot or on SMBs depending on the dive, conditions etc.

A relatively hot topic for the week was how hard it is to actually hit and maintain a 9-10m ascent rate to the first stop.

Logging dives daily and comparing profiles we were all mainly averaging circa 6-8m per min.

If we did hit 9m a minute it felt pretty fast and unstable and was really only achievable on the shot ascents generally not during an SMB ascent.

Just wondered how others hit the prescribed 9m/min in ow.

In OHE the issue could be more pronounced given the profile of the cave or mine, and the slower the ascent the closer the deco profile strays towards a deep stop style ascent.

So does the computer adequately pad the shallow to reflect the slower ascent, or do you pad it to compensate?

Snap. We were probably in the same fish and chip van queue...

 

[Manatee Diver]

Great example I have.
Sent off a DSMB on the lee side of the Tabarka in Scapa. The DSMB went straight up, once out of the shelter of the wreck turned at right angles and disappeared out of sight.
I saw the centre of the spool appear on my small 50m reel, reached over and grabbed my buddies shoulder strap (just as she was about to slap me), I took off doing a superman impression, towing her behind me.
Once out of the shelter of the wreck, everything slowed down, and I had to reel 42m of line back in whilst we started our stop.

About the same thing happened to me there, first 30 feet or so, pretty much straight up, but at around 30 feet there was a different much swifter current and it just went sideways.

And it is really hard to reel your life up if you pay it all out. I remember running a jump reel to zero. I had a work really hard to restart it.

 

[Macan]

The video quality isn’t good but it shows the DSMB at 90 degrees Horizontal.

 

[kensuf]

It is fun as long as you know you have enough line. At 60 ft with a 150 ft spool and you wonder if you have enough line as you watch the thing payout in a 2 knot current.

My rule of thumb is jump with a reel that's at least 50% longer than the depth.

 

[rddvet]

You prefer a reel for deeper dives as opposed to a spool? On the few deeper ow dives I've done I just carry a reel. I think it's easier and safer, especially from depth. I've had multiple people poo poo a reel and tell me if I can't use a spool then my skills suck. I ignore them