dove a little in Key Largo over the weekend.  worst dive was the Spiegel Grove.  unfortunately, the current was running something wicked, and it was a lot of effort just to descend hand over hand on the line.  i had to take breaks not to get winded.  we made it to the bow, but visibility was less than 10 feet, and after a little bit, we just called the dive.

     by far the best dive was Molasses Reef.  this reef shows its wear and tear, but it still retains quite a lot of healthy coral, and the fish variety and abbundance is still quite nice.  here are some pics:

honeycombed cowfish

scrawled filefish

    of all reef fish, i like the "weird" ones the best: filefish, cowfish, trunkfish, puffers.  morays are also nice (we saw two on the Molasses Reef dive).

     i took this video on my trip to Roatan, June 2005.  nothing fancy; i just used the video feature on my Canon SD-110.  sorry, no external lights, so the colors aren't that great.

    watch video

   i stayed with the CocoView resort: great crews, great staff.  i'm not sure if i'll go back to Roatan, but if i do, i'll defeintely go back to CoCoView.   why i ain't going back to Roatan (tongue in cheek) (apologies to Bob Dylan):

i ain't going back to Roatan no more,

no I ain't going back to Roatan no more,

it's hot and is humid,

the dining room's got no AC,

and the sandflies and bugs

have left nothing of me

the itch and the pain i just can't ignore

no, i ain't going back to Roatan no more

i ain't going back to Roatan no more

no i ain't going back to Roatan no more,

the guys at the bank

pack loaded shotguns,

the crazy taxi driver

just absconded with my funds

despite my best attemps to build rapport

no, i ain't going back to Roatan no more

i ain't going back to Roatan no more

no, i ain't going back to Roatan no more,

(repeat ad nauseam)

    i remember from my Nitrox class asking the instructor, if i have

two different mixes, which one should i use for the first dive?

   i don't recall what the answer was.  recently, this topic came up

again, and i decided to run the numbers for myself.

   if you are doing two dives to the same depth, and have two

different Nitrox mixes, should you use the lean mix first or

the rich mix first?

   let's assume two dives to 70 feet.  i have 36% nitrox and 26% nitrox.

which one should i use first?  think about it before you look below for

the answer.

    ok, well... here's the math:

Using 36% first:

1st dive to 70 on 36% for 40 minutes: come out at group O
after one hour surface interval, you are group E
at 26% you have a maximum bottom time at 70 feet of 25 minutes
(EAD of 63, so used 70 feet)

Total dive time using richer mix first: 65 minutes

Using 26% first:

1st dive to 70 feet on 26% for 40 minutes: come out at group T
after one hour surface interval, you are gruop G
with 36% you have a maximum bottom time at 70 feet of 37 minutes

Total dive time using leaner mix first: 77 minutes

   so, it looks like the leaner mix first is the way to go.

   is that what you would have guessed?

 the answer is, it depends.  to the top of the structure

at 70 feet?  sure.  to the flight deck at 140 feet?  it'd be a

waste of time.

 let's do some air planning:

using my SAC (surface air consumption) rate of .8 cf per minute

at 1 ATA, this is what comes out:

descent gas: getting down to 140 feet (at 50 fpm): 9 cf.

rock bottom gas (enough air to get me and my buddy

to the surface should he have a total air failure):

2 minutes at 140 fsw to sort the problem: 16cf
1 minute to ascend to 110 fsw: 9 cf
1 minute to ascend to 80 fsw: 7 cf
1 minute to ascend to 50 fsw: 6 cf
1 minute to ascend to 30 feet: 4 cf
1 minute stop at 30 feet: 3 cf
1 minute ascent to 20 feet: 3 cf
1 minute stop at 20 feet: 3 cf
1 minute ascent to 10 feet: 3 cf
3 minute stop at 10 feet: 6 cf

total rock bottom gas: 60 cf.

total descent and reserve gas: 69 cf.

that leaves me 11 cf to actually use at 140 feet on an AL 80,

which for me is shy of a 3 minute dive (i.e. not gonna happen).

to dive to the max of my NDL with 26% O2 at 140 feet (10 minutes),

I'd need an additional 31 cf (for a total of 42 cf bottom gas).

so, to make a dive to 140 feet for 10 minutes, i'd need a minimum

of 111 cf. that suggests a steel 120 tank.

of course, that doesn't even address whether i'd want to go down

to 140 feet on nitrox to begin with (being a narcosis wus).

let's be safe out there!

      back to Peacock Springs today, for two dives with Simon (from

England, by way of Savannah).

    while in the water at Peacock I for our first dive of the day,

we spotted a pileated woodpecker.  it's a large bird, about

the size of a crow or slightly larger.  the red crest is very, very bright.

pileated woodpecker

       simon and i are getting ready to take our apprentice cave class

next week (also coming along is jeandiver from ScubaBoard).

     we did some drills and had fun.  also, i was trying out my new

Nitek He (i paid way too much for it).  i did find that the interface

is a lot simpler than my old Aeris Atmos 2, which i love. also,

the display was easier to see.  all in all, i am happy so far with the He.

(by the way, the Atmos 2 is being phased out in favor of the new

Aeris XR2.  frankly, other than a $70.00 price hike, i don't see

much of a difference here. ah, progress... we pay more for the

same thing, repackaged.