In situ concrete mattress protection with open hole porosity have been developed and used over the last 10 years as scour protection to wave zones. The paper will present a design method based upon comparison to guidance provided by HR Wallingford [8] following scale model testing on concrete slabbing with gaps. This will allow wider consideration and use of this new protection. Open Hole Mattress is particularly useful to wave zones under open piled jetties where it can readily be installed and pump filled with concrete under piled platforms. Case histories of port applications from Guatemala, USA and Iraq will be presented. A case history of use on the Brahmaputra River in Bangladesh will also be provided where Open Hole Mattress was made in the local natural jute material. The case histories will demonstrate use of the protection system and its use in developing countries.