Awhile ago boat movement placed a strain on the shore power cord for our boat, which caused it to work loose, broke the locking ring on the boat end and almost became disconnected. To prevent this from happening again I designed and built a cord strain reliever out of an assortment of parts on hand that cost maybe less than a $1.00. The carabiner end is clipped to a stanchion. That was several years ago and so far the design has worked out quite well. Simple and cost effective. A different angle of my design shows what used to be a short piece of nylon strap dog leash that I found on the road while running with a carabiner on the hand loop end and an adjustable clamp that secures the working end of the dog leash to the shore power cord.