This research examines the requirements of a capability portfolio for protecting a maritime force against a conventional small boat swarm attack. It provides decision makers with insights gleaned from exploring the trade space between weapon consumption, fuel consumption, and cost against the need to protect the force. Such an attack can deplete a forces resources and create risk to overall mission accomplishment. In this research, the Iranian training attack on a mock U.S. aircraft carrier in the Strait of Hormuz in February 2015 is the basis for the modeled scenario. A notional U.S. carrier group forms the baseline capability. An agent-based simulation scenario models the effectiveness of various capability options added to the baseline. These options include maturing developments such as the littoral combat ship LCSwith modified Hellfire missiles, Spike LR missiles adapted onto autonomous 11-m unmanned surface vessels USV, and advanced precision kill weapon system II missiles carried by Fire Scout tactical unmanned aerial vehicles TUAV. A nearly orthogonal and balanced design, with 512 design points, yields broad insights and ensures an efficient experiment. Partition tree analysis, a non-parametric regression technique, identifies the presence and strength of influential factors. Efficient mixes of LCS,USVs, or TUAVs prove to be critical elements of protecting the maritime force while preserving its capabilities to accomplish the overall mission.