Nitrox?

[dmaziuk]

I haven't been on a cruise, it's what: one day of 2 dives per island? 40-minute dives to 60 feet? Yes, one could get bent on those. One could get bent on nitrox too, it's not like it's a voodoo gas.

Or is it?

 

[Brett Hatch]

I dont have, use a computer.

Wait, what? Are you using dive tables to plan your dives, or just kinda trusting the DMs to keep you from getting bent?

 

[gmerick]

For diving involving multiple days, multiple dives each day, NITROX is definitely worth it. Ramon's resort in Belize, 8 days, 4 dives per day, dive times planned at 1 hour. Part of the group returned early due to air consumption or NDL. I dove 2x AL80's with NITROX and returned with the group at the planned one hour with no concerns on remaining gas. Next trip was Aquacat. Again 2x AL80 w/ NITROX. All diving for the week was small groups (2 or 3 divers, or solo) plus a small guided group. I mostly dove solo, and was on the ladder at the planned one hour. 25 hours under water in a week is simply not practical without NITROX. Not everyone doing resort or LOB diving would consider maximizing bottom time to the exclusion of other entertainment offerings. For me, swimming pigs, iguanas, beach excursions, and ziplines aren't what a dive trip is about.

 

[Scuba Lawyer]

We call it Geezer Gas just because many of us old farts feel we have a bit more energy at the end of a day after 5 or 6 boat dives hunting halibut or lobster swimming hard and covering lots of distance. I know there really isn't any evidence that it has any beneficial effect but at end the dive day I feel better than diving 21% all day. My 2psi.

 

[Belzelbub]

Wait, what? Are you using dive tables to plan your dives, or just kinda trusting the DMs to keep you from getting bent?

Yeah. That was my question when I read it.

I hope it's tables, but I kind of expect it will be **"trust me" diving.

Sounds like the OP is gas limited at the moment, so there is more than one solution to longer dive times.

Improve SAC/RMV. (Or see if slightly larger tanks are available.)
Get a dive computer. (Will allow credit for time spent above max depth.)
Nitrox certification. (Aside from the cost of the course and slightly higher *fill/rental cost, I really see no downside.)

*The shop I use primarily charges between $4-$5 more for Nitrox as compared to air. Rental is the largest difference at $5. Other services like VIP/Hydro and fills have more like a $4 difference. Not a big enough difference for me to worry about.

**A little more on that. There seems to be a growing acceptance of using a dive computer attached to another diver's wrist or console. This goes against every training course I've ever taken. From my first, which was just tables, but still stressed that depth and time should be recorded from gauges and watches worn by the diver. More recent courses that focused more on computers as opposed to tables still continued with this. Maybe it's just me, but I'm not really OK with this trend. In the end, it doesn't affect me as I make sure I've got myself covered.

 

[mac66]

Wait, what? Are you using dive tables to plan your dives, or just kinda trusting the DMs to keep you from getting bent?

Well...to be honest...I've never looked at a dive table. on dives in cruise ports with a maximum of one two tank dive a day I depend on the guide/DM. Most are used to dealing with occasional vacation divers off of cruise ships. Many cater to those types of divers.

And even though we don't go deeper than OW limits they usually put a safety stop in their dives JIC.

Oh...and on my recent dive in Roatan they gave me AL100 tanks because they knew I was a relatively new diver. That worked well, did 45 mins on a tank. Of course depths were only about 35-45 feet there.

 

[mac66]

I haven't been on a cruise, it's what: one day of 2 dives per island? 40-minute dives to 60 feet? Yes, one could get bent on those. One could get bent on nitrox too, it's not like it's a voodoo gas.

Or is it?

Yeah, usually one two tank dive per island, maximum of 60 feet but most don't go that deep. I'd say average is 35-45 feet. Almost always includes a safety stop regardless of depth.

 

[Divin'Papaw]

Well...to be honest...I've never looked at a dive table. on dives in cruise ports with a maximum of one two tank dive a day I depend on the guide/DM. Most are used to dealing with occasional vacation divers off of cruise ships. Many cater to those types of divers.

And even though we don't go deeper than OW limits they usually put a safety stop in their dives JIC.

Oh...and on my recent dive in Roatan they gave me AL100 tanks because they knew I was a relatively new diver. That worked well, did 45 mins on a tank. Of course depths were only about 35-45 feet there.

Given the above details, I would say don't pursue nitrox. Rather, I would recommend you learn to become a competent, independent diver. Get your own computer and learn to use it to execute your own dives. Until you can dive independently without having your life dependent upon a dive professional (DM/Guide), you really shouldn't be taking on nitrox in my opinion.

 

[Belzelbub]

Given the above details, I would say don't pursue nitrox. Rather, I would recommend you learn to become a competent, independent diver. Get your own computer and learn to use it to execute your own dives. Until you can dive independently without having your life dependent upon a dive professional (DM/Guide), you really shouldn't be taking on nitrox in my opinion.

Agree completely.

Getting your own computer and being an independent diver needs to be the first course of action. Otherwise, you are placing blind trust in a DM that you may have just met. Hopefully, that DM is diving the same gas as you, but I can guarantee that the profile will be at least somewhat different. Regardless, there are several instances where divers with their own computers followed their DMs and found out after the fact that there were excursions they shouldn't have taken.

 

[dmaziuk]

Yeah, usually one two tank dive per island, maximum of 60 feet but most don't go that deep. I'd say average is 35-45 feet. Almost always includes a safety stop regardless of depth.

Haldane's original no-limit depth was 30 feet, it's been slightly reduced since but still: with 40 minutes at 40 feet, about the only thing to keep track of is ascent rates. Which a dive computer will track for you, as well as the rest of the useful stuff: depth, no-stop time, depth, surface intervals and so on.

The cheapest ones are just over $200, it's a bit more than the cheapest nitrox course, and you don't need one if you keep doing those kinds of dives and stay next to the DM, but that's what I'd get myself for Xmas before/instead of a nitrox course. (Some are almost small enough to be worn as a watch, but those tend to start in $400 range and presbyopia may be a factor.)