Correction: Georgia (the country) has no Caspian Sea coastline. Its western border is the Black Sea.
The five countries with Caspian Sea coastlines are:
The Caspian is the world's largest inland water body (371,000 km²) — oil/gas, sturgeon (caviar), shipping, geopolitics (Convention on Legal Status, 2018). Georgia is a transit corridor (Baku–Tbilisi–Ceyhan pipeline, rail) but not a littoral state.
Georgia = Black Sea. Caspian = Russia, Kazakhstan, Turkmenistan, Iran, Azerbaijan.