Suunto D9 Sampling Rate versus Log memory

[DavidScubadiver]

When I read that the Suunto stores over 30 hours of dive log memory, I had no idea this was contingent upon the sampling rate. I wound up losing 12 or 13 dives on my last vacation because I did not bring a laptop with me and didn't realize my log book had filled up after only 4 or 5 dives. It sure would have been nice if the instructions gave the "negatives" of changing the sampling rate to 1 second!

Does anybody know of a "table" that sets forth the approximate hours worth of diving that the log book will store as a function of the sampling rate?

 

[trux]

Usualy it is better using common sense than relying on technical documentation. You have to realize that the watch has limited memory, so it can only store limited set of data. You do not need any table as long as you are able to multiply and divide (or have a calculator). If the default sampling rate is 30s (I do not know if that's the case at D9), then if you change it to 1s, you can store 30 times less - it means one hour. You can base your calculation on it then - 2s = 2hours, 3s = 3hours, etc.

 

[DavidScubadiver]

Thanks. That is mildly helpful. The documentation and advertising for the D9 unit says nothing about sampling rates other than it can be adjusted to 1 second. It DOES say the dive log stores ove 30 hours of dive time. Its a deceptive or misleading claim at best. I have noticed for another Suunto model their advertising specifically mentions that the log time will vary based on the sampling rate, and it says precisely by how much.

I don't think its unreasonable for a $1,000 computer to actually come with documentation that provides an estimate of how many hours worth of data it will hold with varying sampling rates, or if your common sense approach yields a correct algorithm, to spell that out in the manual. I do think it is unreasonable to require one to go by "trial and errror" at the cost of losing dive data or requiring premature downloads.

I note that the Vyper "ad" on the website says: "The extensive memory functions include the lifetime history memory and a 36-hour logbook with a dive profile memory. You can adjust the default 20-second sampling rate to 10, 30 or 60 seconds. When set to 60 seconds, you can increase the logbook memory up to 100 hours." That at least suggests the correlation you were referring to.

As for "Usualy it is better using common sense than relying on technical documentation" I don't agree with that at all. If you analyzed your Nitrox at 36.9 and plugged in 37 on your Suunto D9, you'd screw up your no decompression limits because of how the computer is programmed. That's the opposite of how most other computers tell you to program them, so I prefer to rely on documentation than on common sense. Though I was screwed in this instance by wanting to maximize my sample rate and hoping it would not crap out the number of dives I could log.

 

[Volquinum]

Hello DavidScubadiver

Sorry to hear that you had a bad experience.

Check out the technical section of the instruction book. Page 100 on the English version explains the 36 hour log time at 20 seconds. There is also a whole lot of good information on battery life and other elements of how the computer deals with its environment.

My only recommendation is to read the whole book several time from front to back to get all of the information. Little tidbits of information are hidden all over. The D9 is likely one of the most capable recreation dive computers around, but it takes a little time and effort to get all the details ironed out.

Good luck with the D9. For me and several other divers I know, the D9 is the best dive computer we have used. I wouldn’t trade it for any other model.

Volq

 

[DavidScubadiver]

Thank you! I read the booklet cover to cover twice, once before I purchased it! I guess I should have read more carefully or closer in time to my trip. Hard to believe I forgot reading it and when I get home tonight I am going right to the manual (if I don't review from the office online!). I love the computer and was just frustrated to lose my dives.

Still, it is a little retarded to have a single sentence at page 100 that says this, when there is a full paragraph at page 86 with respect to the dive log mode which reads: "The memory will retain approximately the last 36 hours of dive time. After that, when new dives are added, the oldest dives are deleted. The contents of the memory will remain when the battery is changed (providing that the battery has been replaced according to the instructions)." How hard would it have been to change the first sentence above to read, "The memory will retain approximately the last 36 hours of diving with 20 second recording interval."? But, I've heard the manual for the suunto is better than for many other dive computers. Not that that says much.