Slide 16 of 21
   Notes:  
 
- The Modified Surf Index (MSI) is a unitless number which represents the total degree of difficulty of operating conventional landing craft in the prevailing or forecasted surf conditions in the surf zone of a specific beach..  Using various tables and graphs from the Joint Surf Manual the individual surf elements are factored into a formula producing the MSI.
 
- The MSI is a Tactical Decision Aid (TDA) that should be done by two separate agencies (for example, CATF staff and PCS) and the answers compared to ensure accuracy.  This gives a Go / No Go criteria for displacement landing craft. 
 
- The MSI does not take into consideration the state of training of personnel or the state of maintenance of equipment.