You Do Need power plug adapter while traveling from Cayman Islands to Thailand.

Here is Why You Need An Adapter

The outlet and plug type used in Thailand are A, B, C and O and in Cayman Islands are A and B. This is how they look like.

Cayman Islands

In Cayman Islands, outlets of type A and B are in use.

Type A

Type B

Thailand

In Thailand, outlets of type A, B, C and O are in use.

Type A

Type B

Type C

Type O