leadweight
Contributor
I brought my new Cressi Archimede II computer with me to the Cayman Islands last week. After 26 dives and at least 20 hours of diving, it did not break or create any strange log entries. The display has to be the easiest to read of anything out there. It is simple to operate, and the log book shows depth, time, starting time, dive time and average depth.
The gage mode is very nice. Depth and time in minutes are displayed in large numbers in the center. Maximum depth is on the top left and seconds on the top right. When executing a run time plan, it is really nice to have the seconds available.
There is a reset button on the back of the case. It will allow the user to switch back and forth from gage to computer modes. Note that this button resets everything except the logbook. You have to set the time and date after a reset.
As compared to the Aladin Tec that I was also using, the Cressi will allow less no stop time. There is very little difference below 70 feet, but the Cressi was often showing much lower no stop time at 40 feet than the Aladin, especially after 45 minutes or so. In practice no stop time would be about 10 to 15 minutes less on the Cressi, leaving you flying high over the reef, if you did not want to return to the surface.
Some dive planner numbers:
50 feet, Air
Cressi instruction manual: 66 minutes
Actual, first dive of a series: 64
Subsequent dives, actual: 60
Aladin: 66
IANTD ZHL-16 Table: 75 !
Yes, for some odd reason the Cressi manual differs from what is programed into the instrument. On the Cressi subsequent dives means any dive until the computer says it is totally clear. If you are doing only 2 heavy dives a day, that means the first dive of the series is dive one on day one, and all the rest are going to be somewhat shorter. On the Aladin things get back to the base level in a few hours, depending on what you have been doing, but always by the next morning, even after 5 dives with the last one at night.
Is this bad? Well, I don't like the error in the documentation, or their failure to give the "subsequent dive" table considering subsequent is for the rest of the trip. If you are looking for a "conservative" computer it might be good. There are folks who advocate running the Aladin Tec in micro bubble mode 1, to make it line up with a Suunto.
It worked so well in the gage mode that I used it that way most of the time. After all, it was just a backup to the Tec. I suppose some would prefer to have two meters in the computer mode to allow a seamless transfer if one broke. Actually, The Mermaid's trusty hockey puck developed a tear in its strap, so I loaned her the Cressi and heard no complaints, about the meter, that is
Cressi says this unit (most likely made by Seiko) uses a modified ZHL-8 calculation, 12 tissues with compartments from 5 to 640 minutes. The Seiko manufactured unit sold by Diverite has similar features but the manual says it uses ZHL-16. The Cressi manual says it was "modified by Randy Bohrer in order to make a more sophisticated RGBM program. The result is an algorithm very similar to ZHL-16..." Hm-mm, Dr Weinke, is this your RGBM?
Most of you know this unit allows two gas mixes with switching under water. It kind of makes it easy to set mix two for 23% O2 and get away with it, even with nosy DM's, if you want more no stop time. It would still be in line with an Aladin.
Other items: Max PO2 may be set to 1.6 for both mixes. If your computer goes into deco it will give a disconcerting warning first, and then record a "deco" icon in the logbook for every dive that day, so the DM's could bust you. The fast ascent alarm is similarly noisy. It is hard to read the ascent graph (the only hard to read thing on the unit) but the depth readout starts to flash before the audible warning goes off. I managed to set it off twice while turning around in shallow water, despite the fact that the center of my body had remained at the same depth. During normal ascents it was not a problem.
Considering the low on line price ($255 at LP) this is a good buy, for anyone except a person who wants to use it as a primary meter and wants something with longer than average no stop times. Considering how expensive the Uwatec digital bottom timers are these days, it is a decent alternative in gage mode. It will read depth to 656 feet in the gage mode, for those of you who planning a one way trip, or have superhuman skills with a closed circuit rebreather.
The gage mode is very nice. Depth and time in minutes are displayed in large numbers in the center. Maximum depth is on the top left and seconds on the top right. When executing a run time plan, it is really nice to have the seconds available.
There is a reset button on the back of the case. It will allow the user to switch back and forth from gage to computer modes. Note that this button resets everything except the logbook. You have to set the time and date after a reset.
As compared to the Aladin Tec that I was also using, the Cressi will allow less no stop time. There is very little difference below 70 feet, but the Cressi was often showing much lower no stop time at 40 feet than the Aladin, especially after 45 minutes or so. In practice no stop time would be about 10 to 15 minutes less on the Cressi, leaving you flying high over the reef, if you did not want to return to the surface.
Some dive planner numbers:
50 feet, Air
Cressi instruction manual: 66 minutes
Actual, first dive of a series: 64
Subsequent dives, actual: 60
Aladin: 66
IANTD ZHL-16 Table: 75 !
Yes, for some odd reason the Cressi manual differs from what is programed into the instrument. On the Cressi subsequent dives means any dive until the computer says it is totally clear. If you are doing only 2 heavy dives a day, that means the first dive of the series is dive one on day one, and all the rest are going to be somewhat shorter. On the Aladin things get back to the base level in a few hours, depending on what you have been doing, but always by the next morning, even after 5 dives with the last one at night.
Is this bad? Well, I don't like the error in the documentation, or their failure to give the "subsequent dive" table considering subsequent is for the rest of the trip. If you are looking for a "conservative" computer it might be good. There are folks who advocate running the Aladin Tec in micro bubble mode 1, to make it line up with a Suunto.
It worked so well in the gage mode that I used it that way most of the time. After all, it was just a backup to the Tec. I suppose some would prefer to have two meters in the computer mode to allow a seamless transfer if one broke. Actually, The Mermaid's trusty hockey puck developed a tear in its strap, so I loaned her the Cressi and heard no complaints, about the meter, that is
Cressi says this unit (most likely made by Seiko) uses a modified ZHL-8 calculation, 12 tissues with compartments from 5 to 640 minutes. The Seiko manufactured unit sold by Diverite has similar features but the manual says it uses ZHL-16. The Cressi manual says it was "modified by Randy Bohrer in order to make a more sophisticated RGBM program. The result is an algorithm very similar to ZHL-16..." Hm-mm, Dr Weinke, is this your RGBM?
Most of you know this unit allows two gas mixes with switching under water. It kind of makes it easy to set mix two for 23% O2 and get away with it, even with nosy DM's, if you want more no stop time. It would still be in line with an Aladin.
Other items: Max PO2 may be set to 1.6 for both mixes. If your computer goes into deco it will give a disconcerting warning first, and then record a "deco" icon in the logbook for every dive that day, so the DM's could bust you. The fast ascent alarm is similarly noisy. It is hard to read the ascent graph (the only hard to read thing on the unit) but the depth readout starts to flash before the audible warning goes off. I managed to set it off twice while turning around in shallow water, despite the fact that the center of my body had remained at the same depth. During normal ascents it was not a problem.
Considering the low on line price ($255 at LP) this is a good buy, for anyone except a person who wants to use it as a primary meter and wants something with longer than average no stop times. Considering how expensive the Uwatec digital bottom timers are these days, it is a decent alternative in gage mode. It will read depth to 656 feet in the gage mode, for those of you who planning a one way trip, or have superhuman skills with a closed circuit rebreather.
