Surge? Drift?

[Newbie Diver]

dear all

pls enlighten between the difference of surge and drift? also, can anyone help to explain how to control bouyancy when at safety stop, without a rope?

thanks a great deal!

 

[fisherdvm]

Surge is a soda. A drift in the winter is a pile of snow blown across the yard or road.

 

[fisherdvm]

I think of a surge as a larger undercurrent that flows beneath the waves. You'd have waves in regular frequency and amplitude, then a larger "wave" which lifts all the rest of the waves upward, which I consider a "surge". Kind of a large wave that carries all the waves. I think some consider it to be any kind of water movement that behaves like a wave.

Drift to me is a verb. Like a leaf drifting down the river. Drift is used as an adjective in diving. Drift diving is diving with a current or flow of water. It can be in an ocean current, a stream or a river, where the diver heads in the direction of the current flow.

Maintaining a safety stop at 10 to 20 ft can be done one of two way - with perfect neutral bouyancy which is difficult if you wore alot of neoprene and lots of lead as you can float up quite easily with slight changes in depth. But wearing little neoprene and little lead weight, one can maintain neutral buoyancy at the safety stop and hover with little to no fin movement. For me, and other beginners, it is sometime easier to maintain the safety stop with slightly negative bouyancy and gently kick my fins to keep my depth between 15 and 20 ft. If you can not maintain your safety stop and float to the surface with an empty BCD with about 500 psi, then you will need to add a few more lbs of weight the next time. I like to spin around and look at the bottom or the surface, and watch for sea creatures or for surface boat traffics.

 

[don Francisco]

Hi Newbie. Hopefully you won't be for long.

Keeping it simple here's the difference between surge & drift.

Surge is a back & forth motion of the water of a few meters or so. It's usually caused by wave action and occurs near shore. It can be fairly violent and the biggest problem is the risk of bumping into things. Some divers also get seasick underwater from the motion. You manage surge mainly by leaving yourself more distance from obstacles or delicate reefs. If the situation allows you can move away from shore and surge will be reduced.

Drift is different in that it is in one direction only as from a current. It can be fast or fairly subtle, but in either case must be factored into your dive plan since it can carry you a fair distance over time making returning to your planned exit point difficult. Drift can also be managed by drift diving, where the current is used to carry you to an exit point or a boat follows you and picks you up when you surface.
-------

Managing a free (no rope to hold to) safety stop is one of the most important skills a diver must master. Basically it's an extension of the bouyancy control you've been practicing all along, and all the same rules such as proper weighting apply, but it is more difficult due to the shallower depth. Here's a few tips to help you as you master this skill.

1- do your safety stop deeper, 6-7 meters or more, where your bouyancy won't be so dynamic,
you can work your way to doing it at 5 meters as your skill improves.

2- ascend from depth in steps, pausing and re-establishing neutral bouyance every 3-4 meters. This will help control your ascent rate, improve your skill & build confidence, keep you closer to neutral bouyancy, and prevent building up too much momentum as you approach the 6 meter depth.

3- avoid watching other divers rise & sink while doing the stop. Their motion will confuse you as to your own position & you'll be unconsiously chasing a moving target. Instead watch your depth gauge or reference a fixed object such as a pinnacle.

4- control your breathing. Breathe shallower to avoid gaining excess bouyancy or better yet time your breathing to control your depth, inhaling to gain bouyancy as you sink, or exhaling on the rise (remember fin pivots)

5- besides breathing you can fin to manage depth by hovering in vertical trim with slightly negative bouyancy & finning back up if/when you sink, but remember to control your feet since unconsious finning, what I call happy feet, will propel you to the surface. You might try doing the stop in horizontal trim, swimming very slowly in a large lazy circle, planing up or down at shallow angles to maintain depth. This is less than ideal & tends to make others in your group restless, but some new divers find it easier than hovering. I still use this technique if I find myself underweighted for any reason.

6- This should be number 1, but is difficult until more skill is acheived. Minimize your weighting to acheive perfect weight, which I define as being neutral or very slightly negative at 5 meters, with an empty tank (30-35bar), relaxed breathing, and no air in the BC. If in doubt, slight overweight is better than underweight, especially for new divers.

7- last, but most important, relax, relax relax, & relax some more. The perversity of free safety stops is that simply worrying about them makes them much more difficult. You begin to float up slightly, this stresses you, you breath more, which makes you more bouyant, & poof you're on the surface. Trying to swim down doesn't always help since it too makes you breathe harder & you end up fighting your own body. So it's sort of a catch 22, just as it is hard to get a job because employers look for experience, doing free safety stops requires confidence, which you only get from being able to do free stops.
-----
I don't know what type of diving is done in Singapore, but these skills are easily mastered with practice. In Cozumel, for example, where all the diving is dirft diving, free safety stops are one of the first skills mastered. New divers have no choice, since there are no ropes to hang on to.

I'm confident that pretty soon you'll be one of those divers bobbing around at 5 meters in Lotus position while pondering the mysteries of the universe. dF

 

[TSandM]

I had a tremendous amount of difficulty learning to hold a stop, and I think Don Francisco's point #7 was the biggest part of it, although there were technique problems as well.

I'd add a couple of observations or expansions to what he wrote: It is difficult to remain at a single depth if your body is not horizontal, unless you have the discipline to keep your feet completely still. If you are tilted feet down, any kicking will drive you upward. You CAN balance the upward drive with letting air out of your BC and being negative, but it's a sensitive balancing act, and inherently unstable.

If you are horizontal and you fidget with your fins, you just move forward, but at the same depth.

One of the problems with ascents is that when you are ascending, you are by definition not neutral. In order to make a stop, you have to arrest your movement upward (this seems ridiculous even to say, but there's a key in it). Stopping the upward movement means, as a practical matter, letting air out of something . . . that something being either your lungs or your BC. Your lungs have the advantage of being VERY quick to vent, and easy to adjust; the BC requires more futzing and is harder to fine tune, especially at the beginning. So one way to make stopping easier is never to get so far away from neutral buoyancy that you can't stop yourself by exhaling sharply.

What a SBer named Jonnythan told me, when I was asking for help with this, is to inhale and start my ascent, then exhale and see if I stop, and if I don't, let some air out of the BC. What a very fine instructor told me was, "There's a window of depth that you can control with your breathing. It's different for each person, but probably never more than maybe three feet. Get outside of that, and you can't stop yourself with your breath any more, and you have to go to your wing. Recognize which side of the window you're on, and you'll go to the correct place to fix things much faster."

So, stay CLOSE to neutral, and constantly check that you CAN stop your ascent, and it will be much easier to hold a stop where you want to.

Also, ANY visual reference helps. A lot of the time, you have an anchor line, or somebody has sent up an SMB. ANYTHING you can anchor yourself to visually will help you be more stable.

 

[Melicertes]

Awesome posts Don_Francisco and TSandM.

 

[dive_lover88]

Agreed on all that has been said.

Just relax and take your time on getting this. Like what TS&M said, its the breathing that will make the difference. It took me about 40plus dives just to hover at 6-7m without the dang com beeping abt the ascent rate.

Currently I 2lb on my full rig with wetsuit and now able to hover in midwater without much problems.

You need to find a instr and ask his/her opinions on your current situation and monitor it for you. They can and will give you pointers and will also show you how to hover in midwater without a ref line. Just ask.

And also dive more...just dont pick up bad habits as you go along.

Like what don Francisco said, stay deep abt 6-7m, coz at 5m and shallower you tend to float to the surface more easily.

 

[perdidochas]

dear all

pls enlighten between the difference of surge and drift? also, can anyone help to explain how to control bouyancy when at safety stop, without a rope?

thanks a great deal!

Surge is moving back and forth due to wave action above. Drift involves a current going primarily in one direction.

The buoyancy question simply involves knowing how to adjust your BC so that you are neutral. I don't have a good verbal description. I just do it.

 

[String]

dear all

pls enlighten between the difference of surge and drift? also, can anyone help to explain how to control bouyancy when at safety stop, without a rope?

thanks a great deal!

Surge, usually in the shallows and caused by wave motion overhead especially when the sea bed is funneling it. Its an up/down main motion.

Drift is just a current running in a specific direction - its horizontal.

As for how to control buoyancy, correct weighting, the right amount of air in the jacket and use the lungs.

 

[Newbie Diver]

Thank all of you for the great advice! and i hope i really wont be a newbie for long