The pocket erodometer test (PET) is an inexpensive and expedient way to derive the erosion categories of soils. The test involves impinging a regulated jet of water at the end of an undisturbed soil sample and measuring the depth of scoured hole after 20 jet applications. The depth of the scoured hole provides an indication of the erosion category. PET and companion erosion function apparatus (EFA) tests were per-formed on 33 cohesive soil samples from 5 different sites on the island of Oahu, Hawaii. In the EFA test, water is run over a Shelby tube of soil placed at the bottom of a flume. The rate of scour is measured under different flow velocities. PET and EFA tests data were used to develop a plot of the PET erosion depth versus EFA erosion category which revealed that a correlation clearly exists between PET erosion depth and EFA erosion category value, the PET erosion depth that separates medium and high erodibility categories should be revised and the erodibility criteria based on soil classification is not very reliable for Hawaiian fine-grained soils