Navigating underwater from boat dives

[supergaijin]

Squares are pretty simple if the terrain allows.

If you know how much gas you'll be using at a given depth you can use consumption as turning points. Just remember to plan for a healthy reserve for when you will muck it up.

Time can be used if you want to dive for say... 60mins. 15mins North, 15mins West, 15mins South, 15mins East.

The right navigation pattern (square vs triangle etc.) really depends on the terrain as poster have mentioned above.

Just remember to plan for a healthy reserve for because you will muck it up.
Just remember to plan for a healthy reserve for because you will muck it up.
Just remember to plan for a healthy reserve for because you will muck it up.

Everybody makes mistakes. Plan for the mistakes and if you don't end up making them, then the worst thing that will happen is that you'll be pleasantly surprised.

 

[Guba]

My concern is the time element and the multitasking you will be doing. First, navigation is one of the skills that requires a little "growing into" as it applies to underwater. Simply knowing the basics is a starting point, but it takes a little getting used to in order to be proficient. You didn't say how many dives you were going to do before the hunting foray, but navigation underwater takes some practice to become truly proficient. Now, couple that with the fact that you are going to be navigating while doing yet another activity that absorbs a lot of attention, and I fear you may have task loaded yourself into trouble. I know that when I do underwater photography, I often find myself having to think very carefully to get myself back on track. It's easy to become so distracted that navigation becomes a problem.
Until you are well versed and skilled in navigation, I'd keep my hunting within sight of the anchor line (and look up once in a while to make sure you KNOW where it is).

 

[triplecove]

I also find heading down to the anchor and taking the exact depth helps in finding the boat -- the depth given by a depth finder can vary quite a bit from the depth at the anchor.

Untill the tide comes in/out and your depth is +- a few feet

 

[TSandM]

We dive where there are big tidal exchanges. If the viz is so low that you aren't going to be able to find the anchor line if you're a couple of feet off (about the maximum amount the depth is going to change during an hour) then you shouldn't be diving off an unattended boat.

 

[Peter Guy]

On of the things that CAN help is to make your return target bigger than just the anchor line by tying off a line to the anchor and running it perpendicular to the direction you plan to head (down or upslope works very well if there is a slope). Trying to hit a 150 foot target (the line) is a lot easier than a 3 foot (or less) target (the anchor).

 

[nimoh]

On of the things that CAN help is to make your return target bigger than just the anchor line by tying off a line to the anchor and running it perpendicular to the direction you plan to head (down or upslope works very well if there is a slope). Trying to hit a 150 foot target (the line) is a lot easier than a 3 foot (or less) target (the anchor).

what a great idea, never thought of that before!

 

[BKSZEA]

Unless I'm diving right around noon, I've used the sun to provide a general direction. Heading out, sun on the left, heading back, sun on the right. I also used to drop a weighted dive flag about 40-50ft below my boat. My easier to spot the flag than a line/anchor.

 

[rjack321]

Before you decide on how to navigate, figure out what are the consequences of NOT making it back to the boat. Are you going to be swept away into the open ocean to die? If you can live with the consequences of flawed navigation then you have lots of options. If you can't then you need a live boat with someone aboard to follow you and come get you.

In the ocean I typically navigate based on the (reef) structure I'm diving. If I am in freshwater with a flatter mud bottom and low visibility then I run line.

 

[DivemasterDennis]

There is an article in scubadiverlife.com called Navigation for the Recreational Diver that is a good starting point. I wrote it. Another version is in my blog here on SB. It's a good place to start, dealing with vectors, natural object naviigation and the like. I also commend to you a navigation class. Navigation skills are important if you are to be an independent , other than "trail ride" diver, and that skill takes a while to develop, just like peak performance buoyancy. There are no shortcuts, just knowledge and tips to apply and master through repetition.
DivemasterDennis

 

[Frosty]

So me and a mate are planning a boat dive for cray hunting sometime this or next week. For me, this is a first as I've only ever done shore dives.
However, I'm a little lost to as how you would navigate underwater from diving off a boat. I mean, for shore diving its relatively straightforward; point you point the lubber line to the shore and line up the bezel with N. Whats more, you've got this huuuge chunk of land which is pretty darn hard not to miss.
For me, boat diving doesn't seem as intuitive. You've got this small boat floating in the middle of the sea, in which you can only see the anchor line and the hull if your underwater.

So my question is, how would you go about navigating underwater off a boat dive, especially since we won't always be swimming in a straight line? I've read a few articles from googling, but I'd like to hear some of your feedback as well

SIMPLE--Invite "some fella" to join you on the dive. -You hunt for the crays and He will get ya back to the boat