The patented design of the GTR uses 2 dissimilar metals that corrode at a predictable rate. GTR's must be used in salt water. Their corrosion rate depends on the water's salinity and temperature at the depth being used. Care must be taken in rigging up the coiled line to prevent any tangles when the GTR releases the line and buoy. GTR's are also called Pop Ups when used in this application.
Detailed instructions are available.
The waste of fishery resources from ghost fishing traps is a real concern and should be addressed through regulations. The use of GTR's to prevent this waste has numerous advantages over the use of untreated twine or untreated metal. The biggest advantage is being time certain. Door opens outward after GTR releases. GTR is used to open an escape panel in the web after it corrodes.