Deviation from the Dive Plan

[sambolino44]

Plan your dive and dive your plan.

That's a great rule, but really, how many of us absolutely never break that rule?

Mainly what I'm concerned about is, how do you explore new places if you don't know how deep it is?

Sometimes my dive "plan" is more like a number of limits, rather than a proper plan. Like for instance, "We won't go any deeper than 60ft, we won't go any farther than the end of the jetty, and we head back whenever either one of us reaches 1500 PSI." Or would any of you consider that a proper plan?

I've often had a "Plan A", "Plan B", and several contigencies for potential problems, like lost buddy or OOA. But I've also had successful dives where, either the plan was "Let's just go look around." or whatever plan we started with was totally not what we ended up doing, but it still ended up OK. What I mean is, it wasn't just blind luck that we made it back, but that we kept in constant communication, were constantly aware of our situation, and just decided mid-dive to do something else than what we had discussed on the surface, all the while staying within agreed limits.

I imagine some of you may say I'm a disaster waiting to happen, and some may say, "What's the big deal?"

What I'm asking for is some insight into how rigid your plan is, and how much flexibility you allow. I tried to do a search for existing threads on this subject. I know they must be there, but I couldn't find them. Thanks.

 

[rhlee]

I usually like to plan a little more detail about what the dive will consist of. For example, what direction are we going in, for how long... what are we going to do when we get there, how long are we going to stay, etc... For sure, there are times when we agree on-the-fly to push something another 5 or 10 minutes (and the reverse of cutting things short), but I find that spelling things out helps get everybody on the same page so there are less misunderstandings underwater.

 

[TSandM]

It's not at all unusual for us to say the hard deck for this dive is 80 feet, and time will be an hour plus or minus. We do gas planning based on the type of dive, and the dive may be turned on gas, time, or thermal tolerance, depending on which limit is reached first.

Even after setting a time/depth limit, it may get changed on the fly. We had a dive plan for a 100 foot depth the other day, but got to the wreck and it was actually at 85, so we had more time. When the originally discussed limit was reached, a brief conference resulted in us seeing a little more of the wreck before returning. It was appropriate to change the plan based on encountered conditions.

The key is to communicate and make sure all the team members are comfortable with the change and understand what the changed plan IS. Wetnotes or a slate are very helpful here.

 

[Jim Lapenta]

For me it all depends on the objective. If it's just to get wet and screw around then the plan is pretty general. Like this depth, for this time, or this pressure. Also the environment plays a part. It's real hard for me to get lost in our local training lake. At this point I can navigate it using little more than natural nav with a little compass thrown in so headings are arbitrary and just do what we feel like or go to see whatever. Open ocean dives are different. I tend to be stricter with all facets of the plan and do not like to deviate without good reason. Wreck dives as well. When I did the duane last week I had several plans as to where to go depending on current and where we moored. Same with the grove. I followed them with only slight deviation to account for my new buddies experience levels. The reef dives were a different matter as I did them solo and was trying out a new camera so I stayed fairly close to the boat and kept track of my headings and close watch on pressure as I can get absorbed in a task such as shooting photos and I know this. Therefore I make a mental note. Solo and buddy deep dives on another hand are carefully planned out to the last detail. Objective,time, depth, turn pressure, gas needed, and location. Unless the crap hits the fan or I/we run across something REALLY interesting there is no deviation.

 

[Rick Inman]

Like others, it depends on the dive.

We did one recently that was planned to the minute, and we knew exactly where we'd be when, and at what depth - and we followed that plan.

Tonights dive plan was to wave past the docks and say, "Let's go out there," which we also did.

 

[Buoyant1]

When it comes to recreational diving (deco diving is a whole different animal) I think the dive plan can be as loose as you want... When we're diving our local quarry our goal is pretty much to "find the quarry" and end up at the surface of the SAME quarry!

We base it on who has the smallest cylinder and the NDL's on who's using what gas. When we hit the turning pressure of the first person that hit's it, we head NW to the exit point and end the dive...no frills! IF we miss one of the attractions we talked about trying to find, we joke about it and try to find it the next time.

I guess you find new places by saying we're going in there, we'll stop at 20ft for a bubble check, then drop to 60-80 ft and go west until we hit 1000 psi then do a recipocal heading back etc...yadda yadda yadda...

 

[Charlie99]

Another way of looking at dive planning is that what counts is the PLAN FOR GETTING BACK.
In one sense it doesn't matter where you go and what you've done, as long as you always have an acceptable plan for ending the dive at any point.

One way to always ensure the ability to safely complete the dive normally, and to be able to safely abort the dive in the event of reasonable failure is to set limits like the original poster does.

Rock bottom gas planning, ascent pressure, turnaround pressure, maximum dive time, limits on how far you swim, limits on decompression are all ways to ensure that you can safely complete, or at least safely abort, the dive.

My most flexible dive plans are on drift dives ---- the end of the dive is just a simple ascent away, so all that is needed is to pay attention to gas and deco status.

My next most flexible plans are some shallow shore dives at spots that I am familiar with. They are shallow enough that decompression is never an issue. I'm familiar enough with the divesites that I know how much gas it takes me to exit from various points. So I just swim around until I get bored or I am approaching the gas minimum for the particular point I'm at. It's only a bit more complicated when I have a buddy, but early on in the dive I will figure out our relative air consumptions and just use that to scale the needed gas for exit.

Another important concept is to be able to distinguish between "preferred method" and "true requirements". On most dives from a moored boat, it is my preference to return to the boat underwater, but it is not a true hard and fast requirement. I'll turn the dive such that under normal circumstances we will get back to the boat underwater, but I don't necessarily plan the dive (or set lmiits) such that we are guaranteed to get back to the boat even if one of us has a major regulator failure or loss-of-air failure at the worst case time. Particularly if we have wandered around looking at stuff, taking lots of detours, then my turnaround pressure my be well past a half tank.

Obviously, if the divesite is in a place with a lot of overhead traffic and it's important to get back underwater, then my planning will be more rigorous, and I'll add in a lot more fudge factor since the consequences of having to surface are more severe than just an embarrassing "swim of shame" back to the boat on the surface.

Charlie Allen

 

[ClayJar]

Um, me too?

Take diving the open water at a spring, for example, with the basin approximately 150' across and mostly at less than 25' (except for a small "deep" section at about 50'). The plan there is just the NDL, an ascent pressure, and (if applicable) maintain appropriate buddy proximity.

Diving the jetties with some inexperienced friends and the potential for ripping currents if you don't watch times, etc., the plan was much more specific. Getting swept into the shipping channel wouldn't be a good thing. (Of course, they apparently didn't listen to it, as they exited the water halfway through the dive and had no idea the second half was to dive practically snorkelishly on the current-protected inside of the jetties.)

When diving with my experienced buddies at our usual sites, although it implies rock bottoms, NDLs, depths, etc., the dive plan is basically conveyed as something like:

• The usual, eh?
• So, clockwise from the dino?
• Let's shoot the trike, ascend at P, and hang out at the deco bar until everyone else is back on the boat.

As purely recreational no-deco divers, we have significantly more flexibility in most of our plans. We wouldn't consider it a deviation from the plan unless something happened like gear failure, getting blown off the wreck/line, etc. (Basically, anything that conflicts with the requirements of the plan, as Charlie99 was saying.)

 

[GA Under Water]

I carry my Wheel on my BC just for that reason, Plans can be updated in the middle of the Dive.

 

[diverdowndh]

I must admit that I have lots of dives but they are usually "guided" and the plan usually comes from the DM. After the DM gives us the general plan, my buddy (my girlfriend) usually append our own plan/agenda that keeps us within the DM's plan, but gives us what we want to get out of the dive. We both have a slate to communicate, and have dove together enough to be able to figure out what the other wants.
I would guess if we did more "unsupervised" dives (meaning, on our own without a DM) a more defined plan would be in order. I've always wondered about how rigid other divers plans were, great thread!