Visual Sample Plan (VSP) is a software tool being developed to facilitate the design of environmental sampling plans using a site-map visual interface, standard sample-size equations, a variety of sampling grids and random sampling plans, and graphs to visually depict the results to the user. This document provides comparisons between sample sizes calculated by VSP Version 0.9C, and sample sizes calculated by test code written in the S-Plus language. All sample sizes calculated by VSP matched the independently calculated sample sizes. Also the VSP implementation of the ELIGPRID-PC algorithm for hot spot probabilities is shown to match previous results for 100 standard test cases. The Conclusions and Limitations section of this document lists some aspects of VSP that were not tested by this suite of tests and recommends simulation-based enhancements for future versions of VSP.