During a 6 month period, you can stay with a Visa on Arrival (VOA) for maximum 90 days.i.e people can continue the visa runs to Ranong for a maximum of 90 days.

The 90 days can be multiple entry and need not be consecutive.

After the 90 days are used you must leave Thailand and can only re-enter on a Visa, within the 6 month period from your initial arrival.

If you do not get a visa you can not re-enter Thailand until the 6 months are over.

These visas must be obtained outside Thailand e.g. in Singapore, KL, Penang

Once the 6 months have passed you can enter again, for 3 months within a 6 month period with a VOA and so on....

As before:  A captain or crew get only 1 month on arrival, irrelevant of any Visa they may hold.

They then must lay 20,000 Baht to leave Thailand and re-enter as a tourist, either with a VOA or any pre-arranged visa now activates.

On return they can reclaim the bond & the above rules apply (90 days within 6 months etc)

 So, only have one captain & everyone else is a passenger - as before

UNLESS

You come & go regularly on a boat – it seems captain & crew can come & go as often as they want provided they only stay 1 month at a time and remain as crew i.e do not go to Ranong or elsewhere & re-enter on a tourist visa.  There is no 90 day limit of accumulated use.

There are several other types of Visa, including Non Immigrant O, which provide 15 month visas.  These are best applied for in your home country...proof of a boat based in Thailand should allow this type of visa to be issued to yourselves.

The boat can get 6 months on arrival. This is extendable up to 1 year.  If you are based in a marina you can get 1 year on arrival by showing the letter from the marina.

It is possible for the boat to stay up to 2 years