Tuesday, 8 September 2009

Scapa Flow – Review dive log 2007

Map picture

In anticipation of our forthcoming return dive trip to the scuttled WWI German High Seas Fleet I decided to review my old logbook entries and look at the dives we did in Scapa back in 2007. A lot has changes since our last visit… mostly down to the fact that this was my very last single tank dive trip… and back in 2007 I was not qualified to complete decompression.

With a view to organising my gas planning I have also included the max depth (sea bed) of each dive site next to the logged dive depth of the 2007 dives.

Dive No Dive Site Depth (m) Run Time minutes Dive Summary Max Depth(m)
1 SMS Brummer 32.3m 25 Great 36m
2 SMS Karlsruhe 24.5m 32 just ok 27m
3 SMS Dresden 35.1m 29 v. good 38m
4 SMS Coln 33.8m 32 v. good 36m
5 SMS Markgraf 42m 45 “Special” 45m
6 SMS Kronprinz Wilhelm 29.3m 35 good 38m
7 Tabarka 15.2m 48 Great 18m
8 SMS Brummer 34m 33 Great 36m
9 F2 + Barge 17.1m 43 ok 17m
10 SMS Dresden 31.1m 36 v.good 38m
11 Gobernador Bores 17.1m 39 just ok 18m

For those within our dive team it might be useful to review the above sites with a view of formulating dive plans.

My intention is to plan for a bottom time (not total run time!) of between 35 to 40 minutes on all dives below 30 meters while carrying a single 7ltr 100% deco cylinder for decompression. Note: I will be keeping 80 bar as emergency reserve gas, so usable gas will be calculated as follows: Fill Pressure – 80 bar (in twin 12L) = usable gas.

So dive limit will be determined by reaching either 35/40 min bottom time OR hitting Usable Gas limit… which ever comes first.

Deco_Planner

The above dive table will probably become my standard dive plan for dives deeper than 30m but shallower than 40m. As Trimix seems to be ridiculously expensive in Scapa so I am unfortunately forced to dive the 30m + depths on Nitrox mixes. I am not happy about this… but needs must.

For example: a 30 minute dive on 28% Eanx at a depth of 39meters would demand a 1 min stop at 18 & 15 meters, 3 min stop at 12 meters, 4 min at 9 meters and finally 8 min at 6 meters. Total runtime of 48 minutes (including 1 min for final ascent from 6m to surface).

Any dive shallower than 31m I will be utilising a standard 32% Eanx mix.

For the Markgraf 45m I will have to use a 25% Eanx mix. Far from optimal!

I would rather be using GUE standard gases and certainly Trimix 21/35 for the 30m+ range… but the logistics are not forthcoming – as I am the only Trimix diver and the dive boat want me to buy the full Helium J cylinder for €400 stg... that's just too punishing for a single diver to carry – but I will see if I can get Trimix fills on the fly from one of the other dive boats or dive centres when I am over there – therefore just pay by the fill! Fingers crossed.

We shall see. Either way I can’t wait to get back onto and into these huge battleships.

The 2009 Scapa Flow High Seas Fleet Dive team are:

  • Colin (Mr. McB) McBride
  • Brendan (U-boat) McBride
  • Damien (Flash) Joyce
  • Chris (Shooter) Jones
  • Marty (Wing Nut) Johnston
  • Mike (Slob knob) Scott
  • Conor (Floaty Bones) McGrath
  • Mike (The Grif) Griffin

Below I have posted some surface pictures from our 2007 Scapa visit… I look forward to updating them real soon!

IMG_0730IMG_0733IMG_0735IMG_0726IMG_0797IMG_0796  IMG_0795IMG_0727 IMG_0729IMG_0736IMG_0738IMG_0794