A trick for clearing silt in a zero-vis harbor job in Seattle

We had to inspect a piling in Elliott Bay with zero visibility from stirred up mud. Instead of the usual fanning, I tried a small bilge pump on a low setting to push water down and create a clean column. It worked for about 15 minutes before the current messed it up, but it was enough to get the shot. Has anyone else tried something like this, or is it just asking for trouble with more silt?

3 comments

3 Comments

michaelnguyen2mo ago

Hey @shane_ross, a sleeve might actually trap more silt if it hits the bottom.

shane_ross2mo ago

Smart move using the bilge pump. You could try a weighted sleeve around the hose to keep the current from pushing it around so much. Maybe even a small cone to direct the flow better and make that clear column last longer.

hugo_jones211d ago

That cone idea might work but you're forgetting the pump itself is pulling water from the bottom where the muck settles. A cone sitting on the sediment would just suck up a sludge slurry and clog the screen faster. Ive seen guys rig up a floating intake with a foam collar so the pump pulls from the middle of the water column instead. Keeps it clear of both the bottom crud and the top debris. Just anchor it with a light line so it doesn't drift off.