I have been using a D4 for 7 years and it's been great. I recently bought a new D6i and thought I'd wear both for a week of diving to see how they compared. I assumed they used similar algorithms and should match almost exactly.
But unfortunately the D6i didn't live up to expectations. I made two dives each morning for four days in a row. The first dive each morning was to a max depth of 60 to 80 feet (different max depths on different days) and an average depth of 40 to 50 feet. Dive times on every first dive was 45 minutes.
Both computers showed the same NDL for the first dive, but after ascending from the first dive the D6i displayed the "Diver Attention Symbol" (little triangle warning.) The D4 did not display the same warning. I checked my profile and there was no ascent rate violations, never came close to my NDL.
I scoured the D6i manual and found that the warning is triggered if any one of the nine "compartments" used in its algorithm reaches the 75% level at any time during the dive. After downloading the dive data to my PC, I checked the nitrogen loading graph for each of the dives and discovered that one compartment (the middle one of the nine) just reached the 75% level near the end of the dive.
So the computer did exactly what it was supposed to do. I only have two issues and I'm hoping someone, maybe from Suunto, can help me resolve them.
1. I could have ignored the D6i warning, but the computer factored it into my NDL for the second dive. The no deco time for the second dive in the Plan mode of the D6i showed between 10 and 15 minutes less than did the Plan mode of the D4 (e.g. for a dive to 50 feet, the D4 gave me 35 minutes while the D6 gave around 20 minutes.) It was bad enough that my guide was chuckling about the conservatism of Suunto computers (we made a game of comparing our available NDL for the second dive among everyone's computers.) The D6i was ultra ultra conservative because of the issued warning.
The net effect was that I didn't use the D6i for my second dives. I used only my D4, as I've done for years, and everything was just fine. My first dives were fairly conservative to begin with, so it seems that ANY dive I make with the D6i will heavily penalize a repetitive dive. This would seem to practically render the computer useless for a two-tank trip.
HAS ANYONE ELSE HAD THIS PROBLEM, AND IS THERE A WORKABLE SOLUTION?
(Aaarrghh... I should clarify: is there a workable solution besides "get a different brand of computer"? I'd like to be able to use the D6i...)
I'm confident my D6i is NOT defective. My son dove with me on the trip and he has exactly the same computers: older D4, brand new D6i. His D6i did exactly the same thing.
2. Is there a significant difference between the D4 algorithm and that of the D6i? The difference in second dive NDL was significant... and both computers went for the same dive, on the same wrist, literally right next to each other.
Until I can figure out how to deal with the problem, my D6i will sit on my desk and my D4 will continue diving with me.
Thanks, in advance, for any advice!
But unfortunately the D6i didn't live up to expectations. I made two dives each morning for four days in a row. The first dive each morning was to a max depth of 60 to 80 feet (different max depths on different days) and an average depth of 40 to 50 feet. Dive times on every first dive was 45 minutes.
Both computers showed the same NDL for the first dive, but after ascending from the first dive the D6i displayed the "Diver Attention Symbol" (little triangle warning.) The D4 did not display the same warning. I checked my profile and there was no ascent rate violations, never came close to my NDL.
I scoured the D6i manual and found that the warning is triggered if any one of the nine "compartments" used in its algorithm reaches the 75% level at any time during the dive. After downloading the dive data to my PC, I checked the nitrogen loading graph for each of the dives and discovered that one compartment (the middle one of the nine) just reached the 75% level near the end of the dive.
So the computer did exactly what it was supposed to do. I only have two issues and I'm hoping someone, maybe from Suunto, can help me resolve them.
1. I could have ignored the D6i warning, but the computer factored it into my NDL for the second dive. The no deco time for the second dive in the Plan mode of the D6i showed between 10 and 15 minutes less than did the Plan mode of the D4 (e.g. for a dive to 50 feet, the D4 gave me 35 minutes while the D6 gave around 20 minutes.) It was bad enough that my guide was chuckling about the conservatism of Suunto computers (we made a game of comparing our available NDL for the second dive among everyone's computers.) The D6i was ultra ultra conservative because of the issued warning.
The net effect was that I didn't use the D6i for my second dives. I used only my D4, as I've done for years, and everything was just fine. My first dives were fairly conservative to begin with, so it seems that ANY dive I make with the D6i will heavily penalize a repetitive dive. This would seem to practically render the computer useless for a two-tank trip.
HAS ANYONE ELSE HAD THIS PROBLEM, AND IS THERE A WORKABLE SOLUTION?
(Aaarrghh... I should clarify: is there a workable solution besides "get a different brand of computer"? I'd like to be able to use the D6i...)
I'm confident my D6i is NOT defective. My son dove with me on the trip and he has exactly the same computers: older D4, brand new D6i. His D6i did exactly the same thing.
2. Is there a significant difference between the D4 algorithm and that of the D6i? The difference in second dive NDL was significant... and both computers went for the same dive, on the same wrist, literally right next to each other.
Until I can figure out how to deal with the problem, my D6i will sit on my desk and my D4 will continue diving with me.
Thanks, in advance, for any advice!