Here is a picture of the teak chocks I use to secure jerry jugs. It holds 2 jugs. The picture shows
one jug in and one out.
It is fastened to the caprail. They are very secure. Two caveats. 1) Dirt collects under the jugs. 2) After many years of sitting in the same place, the feet of the jugs wore right through the gel coat. I'm going to add some thin teak rails under the jugs to solve both of those problems.