This applied dissertation was conducted to provide the graduate program in marine sciences a valid predictor for success in the admissions scoring systems that include the general Graduate Record Exam. The dependent variable was persistence: successfully graduating from the marine sciences master's programs. This dissertation evaluated other values including the applicant's age, gender, undergraduate GPA, letters of recommendation, and acceptance level (Accepted with Academic Requirement (probation) or Full Acceptance). The writer statistically showed that two values proved most significant in defining a student's persistence: undergraduate major GPA and age when entering the program. An analysis of the data allowed the marine science master's programs to develop an index to assist students to succeed in the program as well as reduce the time to completion. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]