Injected...
About that 7" redfin: Using a very small drill, bore a hole in the belly into the empty cavity inside the body. Using a syringe (needle) inject water (or Hg, but you didn't read it here!) inside. Then, heat up a butter knife and smooth over the hole with the hot blade. The load will drop to the tail and she'll cast like a rocket, then when she hits the water, the load will level out and she'll swim like normal. Water gives a more neutral bouyancy - experiment some. Hg - so I'm told (

)- works the same, but she'll sink because of the density.