Dive like a pro downcurrents tips from tom
PSDiverTom 
says:
SURVING DOWNCURRENTS
T D HANAWAY
MSDT PSDLevel4 PSD/POLICE DIVER (RCMP/GRC)
PADI NAUI IANTD SSI SDI/TDI/ERDI
PSAi PSDA IADRS
DCBC (CANADA)
Halifax NS Cert. SSA DIVER1/ TENDER NO RESTRICTIONS
Diving in South Florida taught me these tips to get your A_S out of a down current so this is 1st hand advice!!But I did submit this to a dive publication
! GRATIS!! Because I believe in diver education!!
AND ALL YOU GUYS OUT THERE ARE MY FRIENDS!!
What are down currents you ask?:
Downcurrents are where a running current sweeps over a wall,or a river flows in.And yes, there are these phenomina out there!!And there are more than one set of conditions that cause them!
CONVERGING HORIZONTAL CURRENTS!
Yes these cause them.Anywhere you have 2 horizontal currents that converge you run a VERY GOOD CHANCE of encountering a downcurrent.You can't compress water as you know,(you can refer to an earlier blog of mine for the physics), so the water is forced to go where? DOWNWARD!! This is a very common occurence near the coast, where the lay of the land (topography) forces tidal flows to converge. (I learned this in Hillsbro Inlet, FL). It can also happen at fronts in open ocean, you can usually tell by very well defined lines of flotsam,(garbage). Apparently according to research I've done these currents can be as strong as 0.25 meters a sec. (Thank you Wood's Hole Oceanographic when I called for info.).
STRONG SURFACE COOLING (CONVECTION)
Cooled surface water becomes more dense as it cools and sinks.This cooler,sinking water has been reported to form into "chimney's for lack of a better word. In the North Atlantic there is one spot that actually takes water from the surface to the bottom at 1500 meters. ( 1 1/4 of a mile!) Pretty scary stuff! I pity my friends in SCAPA FLOW UK that have encountered this.
INTERNAL WAVES
This is another kind of an ocean wave that have a verticle motion. Interenal wavesare formed because of the varying densities of the layers of water from the surface all the way to the ocean floor. These are not tsunami's!!
You can usually spot these guys propagating towards the shore from open ocean and they can sometimes be seen as slick lines that run parallel to the shore.
The BEST WAY TO SPOT POSSIBLE DOWNCURRENTS
Look for well defined lines of flotsam,slicks, or windrows.The lines usually will mark the convergence of currents and therefore a good place where a downcurrent is possible.
SAVING YOUR BUTT!!
If you happen to find yourself and your buddy caught in one of these downcurrent situations you will have a better chance of swimming horizontally to get out of this current than fighting against it. If you're still being pushed downward make a CONTROLLED EMERGENCY ASCENT by inflating your BCD, ditching your weights or both!!
I may not be here today to bore you with my blogs if it hadn't been for a good friend and buddy in Tarpon Springs FL, George Diadonidas,(yes, very greek!). I encountered this while diving with him in Hillsbro Inlet on the OTHER SIDE of FL from where I lived, I just HAD TO dive near the Lighthouse!! Hope you've gained a bit of insite about this crazy phenom as I decided to include this one because I have a lot of good friends in FL and other coastal states.
HAPPY DIVING EVERYONE!!
TOM
PSDiverTom says: SURVING DOWNCURRENTS
T D HANAWAY
MSDT PSDLevel4 PSD/POLICE DIVER (RCMP/GRC)
PADI NAUI IANTD SSI SDI/TDI/ERDI
PSAi PSDA IADRS
DCBC (CANADA)
Halifax NS Cert. SSA DIVER1/ TENDER NO RESTRICTIONS
Diving in South Florida taught me these tips to get your A_S out of a down current so this is 1st hand advice!!But I did submit this to a dive publication
! GRATIS!! Because I believe in diver education!!AND ALL YOU GUYS OUT THERE ARE MY FRIENDS!!
What are down currents you ask?:
Downcurrents are where a running current sweeps over a wall,or a river flows in.And yes, there are these phenomina out there!!And there are more than one set of conditions that cause them!
CONVERGING HORIZONTAL CURRENTS!
Yes these cause them.Anywhere you have 2 horizontal currents that converge you run a VERY GOOD CHANCE of encountering a downcurrent.You can't compress water as you know,(you can refer to an earlier blog of mine for the physics), so the water is forced to go where? DOWNWARD!! This is a very common occurence near the coast, where the lay of the land (topography) forces tidal flows to converge. (I learned this in Hillsbro Inlet, FL). It can also happen at fronts in open ocean, you can usually tell by very well defined lines of flotsam,(garbage). Apparently according to research I've done these currents can be as strong as 0.25 meters a sec. (Thank you Wood's Hole Oceanographic when I called for info.).
STRONG SURFACE COOLING (CONVECTION)
Cooled surface water becomes more dense as it cools and sinks.This cooler,sinking water has been reported to form into "chimney's for lack of a better word. In the North Atlantic there is one spot that actually takes water from the surface to the bottom at 1500 meters. ( 1 1/4 of a mile!) Pretty scary stuff! I pity my friends in SCAPA FLOW UK that have encountered this.
INTERNAL WAVES
This is another kind of an ocean wave that have a verticle motion. Interenal wavesare formed because of the varying densities of the layers of water from the surface all the way to the ocean floor. These are not tsunami's!!
You can usually spot these guys propagating towards the shore from open ocean and they can sometimes be seen as slick lines that run parallel to the shore.
The BEST WAY TO SPOT POSSIBLE DOWNCURRENTS
Look for well defined lines of flotsam,slicks, or windrows.The lines usually will mark the convergence of currents and therefore a good place where a downcurrent is possible.
SAVING YOUR BUTT!!
If you happen to find yourself and your buddy caught in one of these downcurrent situations you will have a better chance of swimming horizontally to get out of this current than fighting against it. If you're still being pushed downward make a CONTROLLED EMERGENCY ASCENT by inflating your BCD, ditching your weights or both!!
I may not be here today to bore you with my blogs if it hadn't been for a good friend and buddy in Tarpon Springs FL, George Diadonidas,(yes, very greek!). I encountered this while diving with him in Hillsbro Inlet on the OTHER SIDE of FL from where I lived, I just HAD TO dive near the Lighthouse!! Hope you've gained a bit of insite about this crazy phenom as I decided to include this one because I have a lot of good friends in FL and other coastal states.
HAPPY DIVING EVERYONE!!
TOM
