As a result of damage from the 2010 Chile and 2011 Japanese teletsunamis, tsunami risk to small craft marinas along the West Coast of the United States has become an important concern. This paper outlines an assessment tool that can be used to quantify the tsunami damage potential in small craft harbors. The methodology is based on the demand and capacity of a floating dock system and uses a Monte Carlo framework to address the uncertainty of input parameters. Detailed numerical modeling and damage calibration data from recent tsunamis are used to benchmark the approach. Results are provided as fragility curves and give a quantitative assessment of survivability. This tool yields an indication as to the survivability and/or failure of a floating dock system of vessels and floating components/piles subject to tsunami events. The objective of the presented effort is to quickly evaluate whether a floating dock is likely to survive or be destroyed by a particular tsunami scenario.