The last thing to enter the water during a mooring deployment is the anchor. Here you see how old train wheels are used as anchor weight for a sediment-trap mooring. Each wheel weighs about 400kg and together they hold the mooring in place while floats with a total buoyancy of about 900kg hold the mooring line straight. This way, a steel cable is stretched vertically in the water column and several instruments like sediment traps, micro-CTDs and current meters can be attached to this mooring line.