A cage full of dirt...

Yesterday we dove to set up a pressure sensor for recovery. This is the fourth time that this instrument has been recovered and each of the previous three times the instrument has been recovered by divers, leaving the cage on the bottom. This time was the last, and se we had a boat to pull up the entire thing: cage, instrument and weights. And thank goodness for that because we found the cage chock full of sand and gravel. I've had to dig sand and gravel out of there before, but typically just a little. This time it was filled to the brim and probably would have taken me a full tank of air just to dig the instrument out of there. Interesting, since there was not appreciable accretion on the sea-floor around the cage. Sign of a wave of sediment passing this location?