Rail for small shelf

I have been looking for a solution for the small shelf below the control panel. Due to the boat rocking, especially when boarding the boat/when rushing about, I needed a rail fitting to stop objects falling off it. The solution was to obtain some sort of rail, but, sourcing it proved difficult. In the end I bought two brass handles and fitted them adjacent to the shelf - works ok and stops my dab radio falling off - one broke recently.