Crew changes are susceptible to delays. The following contingency measures must be in place:
: Verifying passports, Seafarer's Medical Certificates, and STCW (Standards of Training, Certification and Watchkeeping) certificates. crew change guide pdf link
A functional guide will have a table listing nationalities (Indian, Filipino, Ukrainian, Russian) and whether they face visa restrictions at the crew change port. The PDF must specify C1/D visa exceptions . Crew changes are susceptible to delays
If you need a broader scope, consider these additional PDF guides: Seafarer's Medical Certificates