Nitrox needed on Brothers/Daeldalus/Elphinstone liveaboard? & few related questions

[FinnMom]

We were at Deadalus in late March. Saw 2 or more mantas on every dive, even our late afternoon bimble just below the boat. We saw sharks too on every dive at Brothers and Deadalus. Turtles too on some 2-3 of these dives. Maybe 50% of our charter were tech certified and we made air, nitrox (slitrox and trimix dives.

 

[DazedAndConfuzed]

If its more likely to have 3 dives a day, probably better off staying on air. Maybe I can inquire with the ship crew, but then it seems that they require us to determine whether we need nitrox now.

We were at Deadalus in late March. Saw 2 or more mantas on every dive, even our late afternoon bimble just below the boat. We saw sharks too on every dive at Brothers and Deadalus. Turtles too on some 2-3 of these dives. Maybe 50% of our charter were tech certified and we made air, nitrox (slitrox and trimix dives.

People come come pretty geared up for vacation diving. Are there dives that specialized that they need trimix?

 

[MB NZ]

People come come pretty geared up for vacation diving. Are there dives that specialized that they need trimix?

It's deep wall diving, you can dive as deep (or as shallow) as you like.

 

[sphyrnidus]

I've been on ten liveaboards the past five years in the Red Sea and been to the Brothers three times. Mostly we went in March and in the fall, although at the end of Octobre it gets quite windy and the waves get higher. We always dive Nitrox overthere because with 4 dives a day it is saver. On the normal liveaboard Max. Depth (law in Egypt) is 40 m unless TEC diving, which is moslty restricted to the all the people on certain trips. I've never seen people doing trimix while others were i.e. on air.
Most often the Oxygen level in Nitrox is around 27-30%. Checking it is very simple, I always do my SO's tank too. Changing the computer to the actual level is once you know how very easy and as between dives, there is plenty of time, not very time intense.
On average, depending on your skill's level, diving in Egypt is very relaxed. If you want to be guided, fine, if not, that's fine too. Off late it has been rather quite in the Red Sea as a lot of tourists stay away due to the conditions in the Sinaï. But there is no danger so far in the Red Sea area. If you have more question's feel free to pm me.

 

[Oldbear]

PO2 = Partial Pressure or Exposure
FO2 = Fractional Gas (Oxygen) or Best EAN Mix
P = Absolute Pressure or ATA or MOD

PO2 = 1.4
P(MOD) = 40m or 5 ATA/BAR (1 ATA/BAR per 10m and 1 ATA/BAR for surface pressure)

1.4 / 5 = .28 or 28% O2 mix or EANx 28

So I would highly recommend using Nitrox on your liveraboard; any time you can reduce your exposure to nitrogen, especially on repetitive dive, I think that is advisable.

 

[Jai Bar]

I always take Nitrox on each dive- especially during liveaboard which is quite intensive diving (in terms of number of repetitive dives, many of them in the range 20-30meters- and the time intervals between them).

IMHO, it is wise to use Nitrox for added safety. Keep in mind that most divers arrive to the Safari quite tired after long travel, stay awake until late night, not used to the topside temperature of a Red Sea summer, get dehydrated- factor a little for age, overweight and lots of repetitive dives, a couple of beers maybe... Better use nitrox... :cool2:

Problem is some boats using O2 blending may get low on Oxygen if there are too many divers are all going on Nitrox, so the O2 percentage starts getting lower as the Safari goes by, and I had a few occasions that we depleted the whole oxygen bank. Some boats using a membrane compressor never managed to get anything above 30% in the good case, and having a not very reliable O2 sensor is quite common- so try to get a reputable operator

 

[Muddyfox77]

I just returned from this trip a couple of days ago. nearly all dives were drift from the Rib due to currents. I completed all dives on Nitrox, mixes ranged from 27% - 32%. Depths targeted were specific to the dive and location but examples are: Elphinestone: 40m on the Plateau's. Brothers 35-40m hanging on the wrecks watching sharks, Deadalus 35m-40m in the middle of a shoal of 30+ Hammer heads. During the week, we swam with Hammers, Grey reef, Thresher, Silky, Manta Ray, Dolphin + spotted Oceanic White tips but only during a surface interval. Air temp 40c+ water 26c-31c further south. The sites were quiet, 2-3 boats at the Brothers and 4-5 at Deadalus.

As for your question about DSMBs. Please ensure all divers have one and are comfortable using them. I found myself with 2 others heading off the North point of Deadalus in a rip current. In only a couple of minutes we surfaced 200-300yrd from the reef and heading further away in a hurry, if it wasn't for the SMB and Whistles we may still be drifting :blush:

 

[DazedAndConfuzed]

All indications imply that dives will go down to 40m, which would require a EANx 28. But it seems that the mix is random, or changes over time. Wouldn't that mean I could be stuck at a max depth of 33m if I got a mix of 32%? Does the boats give nitrox mix specific to the dive? In sept, don't think the place will be infested with sharks, so we might not be hanging around looking at them.

As for your question about DSMBs. Please ensure all divers have one and are comfortable using them. I found myself with 2 others heading off the North point of Deadalus in a rip current. In only a couple of minutes we surfaced 200-300yrd from the reef and heading further away in a hurry, if it wasn't for the SMB and Whistles we may still be drifting :blush:

me and my wife got the sausage, whistle and she got one of those underwater quackers which also works topside. probably get a mirror and a spool just to be safe. Inflating it on the surface is easy, but it being the type with the blow in valve, not sure how easy it would be to use underwater.

 

[sphyrnidus]

Most often the % is 27 at the beginning of the trip and then gets a bit higher as the concentration goes up over time. More often then not it will be 29-30% which is perfectly safe at 35-38 m. There will most certainly be sharks on most dives, depending on the area you go to. But at Brothers and Daedalus there are most probably hammerheads and Longimanus in September.
Currents vary, I've been at Elphinstone with zero current i.e. as well as very strong current.
It is required by almost all operators to carry an SMB. A couple of years ago five divers got lost due to the current at Elphinstone and only one survived because he swam the 5 km to shore...

 

[FinnMom]

Wow, I had never heard about the accident sphymidus just cited. Can someone give me links to more on the story in English?