underwater vacumn scooter

[newfoundlander]

I am a sea urchin diver , i dive for sea urchins in approx 25 ft of water, I put the urchins in a bag that is 6 ft long and the rim of the bag is a milk crate with the bottom cut out. 1ft x1ft ..
as i collect the urchins that are about the size of a orange , I sweep the water with my hand and the trust from my hand sweeps them into my bag because the are not stuck on the bottom very well and they are very light.
lately i have been looking at those little small scooters and i was thinking that the trust from the prop could force the unchins in my bag or would be good to make some sort of vacum to suck them in. Is there a scooter that has different speeds that I could put it on, low to blow or suck the urchins into the bag and then could be turned on high to get me to the next pile of urchins. or can you buy some sort of underwater vacumn. I am sure there has to be a better and faster way to harvest them, any ideas would be great, thanks

 

[archman]

Why are you collecting so many urchins? You don't eat the gonads do you? Yuk! My guess is you're harvesting those "green" Strongylocentrotus types (forget which species is up there), the ones that have the periodic mass mortalities.

 

[newfoundlander]

yes , it is those green ones, they are very spiny and fills my fingers full of spins no matter what i put on my gloves. and the reason i get them is i work for a fisherman that sells them to japan , they eat the spawn in them.

 

[Scubaroo]

Hehehe a small airlift dredge may work! No idea if it would, but that's the direction I would be looking. Just suck them up into a catch bag somewhere over your head at the end of the dredge pipe. Might really screw the visibility though.

 

[changinwa]

Newfoundlander,
I am an urchin diver in Washington and Alaska. You probably have large tides like we do. I find that where we harvest these urchins, we are prone to high currents. I prefer to harvest as streamline as possible and have a sugestion to modify your construction of your bag to include a flexible opening made out of 2" flexible hose, this allows the bag to conform to contours of the bottom. I have used skooters for survey work but only got in the way during harvesting. Good luck Joe!

 

[FredT]

After a few minutes thought I believe a scooter powered thing could be made to work. Probably not simple and not cheap as the urchin bypass past the prop would be tricky to avoid damage to the urchins, but possible.

An airlift type thing would be dirt simple. Plans for the suction head on a 2" unit are posted on The Deco Stop. The problem is that the airlift will work at slack tide no or low current conditions only.

FT