How Much Reliance on Dive Shop Planning?

[TMHeimer]

I'll add that the Mares Puck also does nitrox--mine was $150 Canadian. I did the Deep Course without one, but the boat dives here are mostly wrecks on the bottom, so square profiles. The instructor said it's a good idea to buy a computer if your going to be doing regular "deep" diving. He probably meant below 80' or so, but I'd still get one for depths shallower than that. Renting one is OK, but as someone pointed out elsewhere, after 10 boat trips you've paid for one anyway. I also use watch, depth gauge and tables (most of my dives are square profile). That's good for a backup to the computer. Or as some suggest buy a backup computer in case your regular one dies and you are on a trip with multi day dives. You can't use the backup between two dives since the RNT from dive 1 isn't recorded. Thus, tables for that 2nd/3rd dive.

 

[Jim Lapenta]

Here's another thing to consider - on a deeper dive why would you trust a shop to plan it for you? It's your dive. Saying that the shop does these all the time and would not do anything to put you at risk is foolish and could get you hurt. The people at the shop don't know you. They don't know your skill or comfort level.
They may decide that it's ok to take you through the wreck.
That could put you into deco.
It's also called a "trust me" dive. Those have gotten people killed.

 

[dmaziuk]

That is exactly why I made the original post. The first dive is 75' for 30 min. The eRDP shows the max no decompression time at 75' is 35 min. IF the dive goes a little deeper, say 80', and IF it goes for 31 or 32 min, that puts it over the no decompression time according to the eRDP.

If you ran your dive plan and you don't like it, for whatever reason, then don't do the dive. If you're looking for someone to reassure you that dive's OK, then listen to your wiser half: take the word of the professionals who's done this dive for 40 years and have a vested interest in not bending their customers, over that of a bunch of voices on the Internet. You may get bad advice from either, I firmly believe in "I heard it on the Internet so it must be True(tm)", so...

How do you plan to do your 20 dives/year? A computer's really great if you go on a 7-day diving vacation and clock 3 dives a day for 6 days straight. That's when you need to worry about residual gas loading. If you're doing your 20 dives one dive per fortnight, meh. Just watch your gauge and don't go deeper than planned.

I'm not trying to talk you out of buying a computer, everyone should have one, but it's not going to make that dive any less or more risky. All it'll do is show you how close your eRDP guesstimate was to the real thing. If that's all you want, you can rent the computer for the dive for about $10, your op should have them and shouldn't charge much more than that.

Edit: quick google suggests that it's a textbook square profile dive, the exact kind one doesn't need a computer for. And pikiwedia says the bottom is at 80', you'll need a shovel to go any deeper.

 

[ScubaWithTurk]

That is exactly why I made the original post. The first dive is 75' for 30 min. The eRDP shows the max no decompression time at 75' is 35 min. IF the dive goes a little deeper, say 80', and IF it goes for 31 or 32 min, that puts it over the no decompression time according to the eRDP.

Now I know the entire dive won't be at 75', or 80', but I don't know what the max no decompression time is for the particular dive profile the operation uses. My question was whether to trust the people that have been doing it several times weekly for decades, or to carry my own dive computer. I've been convinced, and will carry my own computer.

The use of the term "perilously" is because of my own self imposed conservatism here, particularly because we are really just starting out, with only 8 dives so far. It's really the wrong word to use here. My understanding is that the time the eRDP is giving me is conservative, meaning going to 75' at 35 min is a safe dive. My concern is that the dive may go a few feet deeper, and may go for a few minutes more - I don't know that, but I want to prepare for that. It is clear to me now that the only way that I will be comfortable if that happens is with my own computer.

Am I missing something here? I am shocked that no one has mentioned his dive count and the fact that this is a wreck dive down to 75 FSW. This is the first thing most mention when people post above a dive that is "beyond their skill level in relation to dive count/experience"

 

[dmaziuk]

Am I missing something here? I am shocked that no one has mentioned his dive count and the fact that this is a wreck dive down to 75 FSW. This is the first thing most mention when people post above a dive that is "beyond their skill level in relation to dive count/experience"

I suspect the only problem with his level of experience is his air ain't gonna last 35 minutes at 75 feet, so the whole NDL thing is moot anyway.

 

[ScubaWithTurk]

I suspect the only problem with his level of experience is his air ain't gonna last 35 minutes at 75 feet, so the whole NDL thing is moot anyway.

That is very true!! I would be interested to see what his dive profiles looked like for the the first 8 dives (psi at start, ending psi, max depth and dive time)

 

[stephen1254]

To piggyback off this comment, if you both have a computer then you have redundancy with your dive buddy. If your computer fails at least you can



Am I missing something here? I am shocked that no one has mentioned his dive count and the fact that this is a wreck dive down to 75 FSW. This is the first thing most mention when people post above a dive that is "beyond their skill level in relation to dive count/experience"

That's a reasonable comment. The dive is around the wreck, not in the wreck. We asked the same question of our instructor - were we ready to do that dive - and he was completely comfortable with it. It is a dive that his operation does as well, and that he personally has done over a hundred times. We didn't go out with him to the wreck, because it meant a much longer boat ride than the shop we are using in May.

 

[AdivingBel]

If you are going to get into vacation diving on an annual basis, having your own dive computers is a good plan. In some instances even in warm water, high viz diving they may be required by the dive op to do the dives you want to do, so best to own your own and learn how to use it. Renting the remainder of your gear should be fine as long as you are using a reputable dive op. A bit of due diligence researching in advance is worth a lot. For common dives of these types (and the Rhone is one) a reputable dive op will give you a good briefing and will probably set a max depth, time limit, and may even provide a guide. They have done this dive many times and as long as the weather & sea conditions are benign, you should be fine, but having your own computer is still a good idea. Be straight up with the dive op in advance and let them know you are new to diving. Listen closely to the dive briefing and ask questions if you need to. If something makes you uncomfortable ask for assistance and don't be afraid to thumb the dive if it doesn't feel right. It's all part of the process of learning and getting comfortable with your new hobby. Good luck and have fun.

 

[scubadada]

Hi @stephen1254,

I may have missed it, are you nitrox certified? If not, do the course online and then go to your LDS to go over your test and analyze a couple tanks. You should definitely use a computer, but can rent one if you don't want to purchase at this time.

 

[diversteve]

Mares Pucks are $150 New instead of a used Zoop.
Mares Puck Wrist Computer

Puck Pro's are $195 new.
Mares Puck Pro Wrist Computer

I've dove the Rhone with DiveBVI. You can't get much deeper than 75' since the bow is in the sand at that depth.

The entrance in the bow is the same place they filmed the famous scene in "The Deep" where Jackie Bisset exits quickly. It's an easy dive and the sides of the ship are open in places so there's "outs" if you're not comfortable with the overhead obstruction.

Also do both halves (2 dives) - I found the back more interesting - there's a big driveshaft, a lot of mechanical stuff - even a small silver spoon welded to the deck by electrolysis. In one area a few feet of marble floor survived. IIRC the back is a bit shallower and runs uphill.

At the very back is a huge prop - you don't even realize what it is at first until you swim between it and the rudder. The back is collapsed so you mostly swim over it - or along one side you can get under the deck but it's all blown out on that side so there's no penetration possible.Lots of stuff lives there since it's been down so long.

Our "newbie" diver did it as dive #12. without issue. If you go with DiveBVI there will be at least one DM in the water - possibly 2 - one leading and one trailing the group. Actually they're all instructors afaik.