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Counter ballast - horizontal separation
- Thread starter Unclejake
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 90 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
How longs a piece of string?
With variables like current wind waves etc its hard to say.
My counterballast is 3.2m from the rollers. I havnt had any issues with that distance apart but usually only down 50m with calm water.
The pfi setup would be worth checking out.
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With variables like current wind waves etc its hard to say.
My counterballast is 3.2m from the rollers. I havnt had any issues with that distance apart but usually only down 50m with calm water.
The pfi setup would be worth checking out.
Posted via Mobile Device
Id doubt that 3.2 is safe for 100m dives with current or waves. Pfi is performance freediving international. They have a counterballast cube thing which Kurt and Martin made i think which has various lines on it and scuba deco stop lines. You could also check out Kieran hibbs he did up a funky one floating on tyres.
Thanks Will. 6 meters had been my target, but it is hard to find a way to build that separation into a RIB and still be able to actually use and move around inside the boat. I need at least one boom well above the waterline (2 meters above the water would be great)
Having the booms running across the boat (port to starboard) is the best use of the internal space, but adds to the capsize risk.
There isn't much to drill into or weld to on a fibreglass RIB
Having the booms running across the boat (port to starboard) is the best use of the internal space, but adds to the capsize risk.
There isn't much to drill into or weld to on a fibreglass RIB
You can limit the horizontal travelling of the counterweight falling down by getting it into a cone-shape.
Maybe run the system along the the length of the boat, with the line on the stern, reducing the line movement in the waves. On the bow , a few meters under the water the counter weight, again to reduce the rocking of the boat.
Your plate could also be small and cone shaped, decreasing drag during retrial.
Use big quality pulleys, because of the long line you need more weight and need to reduce the rope resistance.
As to distance, factors like waves, wind, current are important. I think 6m for a 100m depth is rather small. I think I heard recommendations of 1m / 10m of depth, so for a 100, a 10m beam.
You could transport the rig using for instance 3x 3m tube beams, assembly on location, have your boat and beam parallel to the current with a v-rope and water anchor and do 1 test run before you dive.
Be sure to test you setup thoroughly.
If your beam is to short a crash helmet could be needed.
Just my thoughts, I hope they make sense.
Maybe run the system along the the length of the boat, with the line on the stern, reducing the line movement in the waves. On the bow , a few meters under the water the counter weight, again to reduce the rocking of the boat.
Your plate could also be small and cone shaped, decreasing drag during retrial.
Use big quality pulleys, because of the long line you need more weight and need to reduce the rope resistance.
As to distance, factors like waves, wind, current are important. I think 6m for a 100m depth is rather small. I think I heard recommendations of 1m / 10m of depth, so for a 100, a 10m beam.
You could transport the rig using for instance 3x 3m tube beams, assembly on location, have your boat and beam parallel to the current with a v-rope and water anchor and do 1 test run before you dive.
Be sure to test you setup thoroughly.
If your beam is to short a crash helmet could be needed.
Just my thoughts, I hope they make sense.
Thanks Kars, that all makes sense.
I am a bit concerned about having the rig running fore-aft as that would increase the chances of the diver (or safety divers) whacking the outboard motor when ascending. I don't want to damage the prop of course
I need to think more. A fiberglass RIB is a tricky thing to try to mount long, strong stuff to. I may run the booms on an angle to fore-aft, but that will impede moving around inside the boat a great deal.
This is hard
I am a bit concerned about having the rig running fore-aft as that would increase the chances of the diver (or safety divers) whacking the outboard motor when ascending. I don't want to damage the prop of course
I need to think more. A fiberglass RIB is a tricky thing to try to mount long, strong stuff to. I may run the booms on an angle to fore-aft, but that will impede moving around inside the boat a great deal.
This is hard
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Maybe have a little boom/ beam from side to side over the stern, paralel to the plank where the motor rest, so that the cw boom can rest more outside and the counter ballast side diagonally cross over the bow. It would help to have the diveline much further from the propeller (You can put a bucket over the vertical tail end as well ) and also leave much more room inside of the boat.