Navigation / Positional Awareness

[tursiops]

No...one must orient that on the onset...take notice while swimming out as the chance of the ripples changing during an hour Dive is remote.

So what did you mean by perpendicular?

 

[RTC'83]

Before I jump in I take a compass reading to where I am heading, note position of the sun and make sure I pay attention to the dive briefing. Note all nav info on my wrist slate. Once I jump in and start my decent, I pay close attention to my surroundings and depth. I keep track of kick cycles and note current.

 

[Jack Hammer]

I find it helps to make a quick mental note before descending of the heading, then as the dive progresses to periodically make mental notes. I'll usually note what angle I'm crossing ripples on the bottom, things of interest with depth, what side of me a wall is on, direction of currents, etc. Then occasionally glance at my compass. It gets much easier with time and experience to more easily find your way around even in places you've never been or while scootering. Like most things, practice helps.

 

[flyboy08]

Run a line

 

[TMHeimer]

At times I check the sand ripples if available. I don't count kick cycles on Atlantic Shore dives here in NS because at times there is a very slow tidal current which can make a difference going with or against it. I used to point out to students how you could drift in or out in relation to the surface training float. Not a strong current at all, but enough to throw off kick cycles.

 

[kablooey]

Navigation starts before you even get your feet wet.

• While still on shore, or on the boat deck, take out that compass and get some basic bearings.
• Direction to shore, direction of shoreline, bearing to target, return bearing, etc.
• Have as many members of your team participate as possible.
• Trying to take bearings while bobbing on the surface just prior to descent is not effective.
• Remember, a compass is useless if the first time you look at it is when you're lost underwater.

Look for "landmarks" throughout the dive, but especially at key turning points.

• Note the depth at the point of your likely ascent.
• Turn around often and look back. See how the route will look on your egress..
• Note your dive time at the turn-around point to track your return run.
• Note the direction of the current. Position of sun, and direction of waves if you can see them from depth.
  
• Utilize your senses: Listen for waves crashing on shore, rocks being tumbled in the surf, the boat motor, etc.
• Natural indicators like ripples in the sand, lean of plant life, depth of thermocline, etc.

Have a Lost Buddy Plan.
(This is so important.)

• Be sure all on your team know the Lost Buddy Plan, and promise to follow it.
• Have a team leader, but also be sure everyone takes responsibility for knowing where they are and what to do if they get seperated.
• Position an experienced competent team member at the back of the group to wrangle strays and slow pokes.

Counting fin kicks?

• That only works if you're Rainman.
• Are you really going to count for a sixty minute dive? (Ok. I just know I can't.)
• Time may be a better tool, but that's not perfect either.
• Constant awareness and observation work best for me.

 

[tursiops]

Trying to take bearings while bobbing on the surface just prior to descent is not effective

Why not?

 

[kablooey]

Why not?

Sorry, probably "less effective" would have been a better phrase.

• Low angle of view. Better view standing on shore or boat.
• Poor opportunity for discussion and information dissemination. Better when team is dry and not task loaded.

Just in my opinion based on experience in west coast diving, and dive leadership.
Divers often wear hoods here. That makes it hard to hear instructions sometimes
... or at least that's what they tell me later when we find them.


.

 

[Kharon]

I normally dive solo from shore but my process is the same from an anchored boat. 1st I always take a compass reading perpendicular to the shore (or the direction of the dive). From shore I will leave a slightly inflated, weighted SMB at a specific depth along that perpendicular. In the case of the boat I note the depth of either the anchor or the mooring.

I wander on my dives but keep either left or right of the marker/indicator. Since I am randomly following what interests me, taking a compass reading with every change in direction would not only be annoying but also impossible to keep straight without writing them down.

When I want to return I simply ascend to the marker depth and head the opposite direction of my dive. If I was wandering right I turn and go left, or visa versa. From shore I will hit my SMB, pick it up, check direction with the compass and hit my exit exactly. From a boat I hit the anchor or mooring and I am there.

 

[Aloha Joe]

Lots of good stuff here, thanks.

Today I did some shore dives. First dive was a rectangle pattern after a coastline surface swim, and just with noting the 4 different headings I had such a better sense of where I was. Still lots to take in and practice but at least it feels good to be working on this.

The Perdix was awesome for this - I have the small compass/heading in the bottom row.