Buying 1st Dive Computer

[KomdoDiver]

I am going to buy my first dive computer. I was going to buy a Suunto D4I but after reading through Scubaboard I have read a few negative posts about Suunto computers. Are these posts justified and is there another brand of dive computer worth looking at, or are Suunto computers a good purchase for a 1st computer.

 

[Krazyklaws]

I've had my Suunto D9 for years and I love it. Lots of people knock them, especially the air integration but I've never regretted buying it. Had an uwatech before that and it was ok too, but I prefer my Suunto.

The algorithm on the Suuntos is a little conservative, but its never given me any troubles.

 

[drrich2]

If you read over the threads debating Suuntos, I think this is the gist:

1.) Quality computers.
2.) Decent interface in the judgment of some. Not going to be like an Atomic Aquatics Cobalt, I'm thinking.
3.) Strong presence internationally so outside the U.S. might have more places it could be fixed if needed.
4.) Algorithm is more conservative than some competitors. In other words, to varied extent depending on some specifics as to how you conduct your dives, it will cut your dive time short.

Let's take a look at 4.), since that's the 'sticking point.' What does a 'conservative' algorithm mean in real world practice?

1.) Cuts your dive time shorter, which is 'safer' in theory. Then again, so is staying on the boat & not diving. Be mindful that people with 'liberal' computers have the option to choose to surface just as quickly as Suunto users. You don't have to take your NDL time to the limit if you don't want to!

2.) If you dive with people who have liberal computers, yours is apt to try to 'call the dive' (get close to running out of NDL time) before theirs. This could lead to you cutting a buddy's dive short. You may be fine with 'safer' conservative diving, but your buddy with a liberal computer may not. Finding readily available quality dive buddies isn't always easy. Some people report that the NDL reduction with Suuntos is small and much-ado-about-nothing; others have reported more substantial differences.

3.) If you go out on a charter boat op. or live-aboard, and they find out you 'went into deco.' (violated a NDL), some will 'bench' you (no diving) for a time (maybe 24 hours?). Your attitude toward paternalistic 'nanny state' practices may affect how you view this.

Richard.

 

[KomdoDiver]

Drrich2 thanks for the informative post. I have got 2 liveaboard trips booked. I can see how diving with a conservative computer versus your buddy's liberal computer could create real problems on a liveaboard trip. The last thing you want on a liveaboard is a 24 hour ban. I will have to do some more research before I purchase the computer.

 

[altaskier]

I've been on liveaboards diving with nitrox 5x per day and have never been limited by my Suunto. I take care to make slow ascents.

As an over-50 diver, I prefer a larger display than what the D4/D9 computers offer, though, so I prefer the Vyper Air/Cobra 3 size displays (I have a Cobra 3).

 

[Willar]

I've done live-aboards and 4-5 dives per day trips with the Suunto Cobra without getting "benched." I like that it's conservative so I don't get bent but I've not had a problem getting locked out of dives or cut significantly shorter than other divers. I do watch the NDL time so I don't get into deco (mandatory stops) with the Cobra by getting shallower if I see the NDL time getting lower. The difference to other computers seems slight to me, but I don't dive to 120ft every time. Also be sure to watch your rate of rise with the Suunto as it will penalize you with a long safety stop if your rate of rise goes much over 30 ft/min.

 

[buddhasummer]

Drrich2 thanks for the informative post. I have got 2 liveaboard trips booked. I can see how diving with a conservative computer versus your buddy's liberal computer could create real problems on a liveaboard trip. The last thing you want on a liveaboard is a 24 hour ban. I will have to do some more research before I purchase the computer.

Given the prevalence of Suuntos this may not be much of an issue in reality as the most conservative computer calls the dive. I guarantee you you will not be the only person with a Suunto. Most liveaboards have a 50 min or 50 Bar max limit anyway and unless you are diving with divers who all have awesome air consumption the dive will be called before you go into deco anyway. DMs on liveaboards tend to dive conservatively and someone almost always runs low on air before getting anywhere near deco. Good luck.

 

[drrich2]

Willar:

I believe it probably varies by live-aboard, but it's my understanding that IF you violate NDL and the crew finds out about it (and at least one checks after each dive, per one of the discussions on another thread I've seen here before), then they're apt to bench you.

You've not violated NDL.

As for this:

I like that it's conservative so I don't get bent...

You can also dive conservatively with a more liberal computer; just don't push the NDL limits as closely (and some people do 5 minute safety stops instead of 3 min.; also see the recent thread talking about deep stops). And some computers are marketed as 'dual algorithm' - you can choose a more conservative algorithm if you wish.

It seems a lot of people are diving 'liberal' computers without getting bent, too. Seems you don't have to dive a conservative computer to not get bent.

Richard.

 

[Willar]

Richard, I agree with all your points. My belief is the Suunto being conservative is fine with me because I want to be as safe as possible while diving. I just get tired of people saying "too conservative" as I think it's safer this way because none if us know for sure exactly when we might get bent. Plenty of people have acceptable computer profiles but still end up with a chamber ride. Each diver can chose how much risk they want.

 

[drrich2]

Did some checking. A popular charter to the Flower Gardens is the M/V Fling. From their web site FAQ:

Computer/Dive Table violations:

We take a dim view of violating decompression status on

computer or dive tables. Any diver found in decompression

violation of either their computer or dive tables will need to

follow the omitted decompression steps of their computer or

tables. This usually involves a 12 or 24 hour extended surface

interval. The only exceptions are: (1) in the case of a diver

wearing 2 computers, the more conservative one is in DECO,

or (2) the obvious failure of a computer, in which case the
diver must switch to tables for the following 24 hours. Failure

to turn on a computer prior to entering the water or failure to

correctly set the breathing gas is not considered failure of the

computer. In this case, the diver will be required to switch to

dive tables for the following 24 hours. The boat divemasters

are required to visually inspect each diver’s computer at the

time the diver returns to the boat and obtain the diver’s profile

for the dive.

Also:

Dive profiles?

The boat-imposed depth limit is 130 fsw

for the first dive of the day ONLY, and 100 fsw for all subsequent dives. Dives must be planned within recreational limits—no planned-

decompression dives are allowed. Within those parameters,

buddy teams plan and execute their own dives. Dive times are

set by the boat crew. Bottom times are limited only by your

no-decompression limits, air consumption and common sense.

I know that 'follow the leader' guided group dives are common on some trips (particularly the Caribbean tourist-catering charter boat op.s). In that case, the scenario BuddaSummer lays out has been my experience with 2 tank cruise ship diving; you probably won't hit an NDL with 2 spaced out guided tourist dives, each with moderate-size groups all diving 80 cf tanks.

But if you dive an operation that lets you do your own thing, and stretch your bottom time if you can, it may be different.

Richard.