Can I enter Thailand with a retirement visa by yacht or only by plane?

This link below might be helpful regards the process, regards your long term retirement visa, I’m not sure but it may possibly open a can of worms though if you are designated as part of the crew though

This is from ChatGPT:

Entering Thailand by private yacht involves several steps:

1. Port of Entry: Identify an official port of entry, such as Phuket or Pattaya.

2. Customs and Immigration: Upon arrival, you must check in with Customs and Immigration. Ensure you have your passport, yacht registration, and any required visas.

3. Cruising Permit: Obtain a cruising permit from the Marine Department if you plan to stay in Thai waters for an extended period.

4. Documentation: Have all necessary documentation ready, including proof of ownership, insurance, and a list of crew and passengers.

5. Health Regulations: Be aware of any health regulations, including vaccinations or quarantine requirements.

6. Fees: Be prepared to pay any applicable fees for port services or permits.

It's advisable to contact local authorities or a maritime agent for specific requirements and procedures before your arrival.

You should be able to enter any border, by land, air and sea with a Non O or No O-A e-visa. The issue is Visa On Arrival and land/sea borders.

You arrive at port, go to the port Immigration Office with your passport and visa and get stamped in