I also work on ships doing repairs (boilers) so inconsistent times. I got pulled over years ago and told get a visa. So got one in Savanakhet in those days (quick to do) Got normal visa and extensios during covid.
Last year went back to doing extensions simply because didnt have time to do a marriage visa. They still kept telling me i need a long term visa when i came in even though days in country were less than 120. One time showed them my signed seamans book and photos didnt make any difference.
If you have never got a long term visa before, you should be ok. If they have on record that you are married here you could have issues
You give your country you leave from this is primarily for health reaons. If you are coming from a country that requires you to show a yellow fever certificate. Your TDAC will then require you to upload a copy of your vaccination certificate. For flight it is the flight that lands in Thailand. I work a lot in Africa so my first entry after May I went and asked to clarify everything as we used to have to fill out a seperate form. You still have to go to the booth in airport and they check your seat number and give you a slip. Basically if you become ill they can see who you were sitting next to
Getting Pu Yai bans signature also took me the longest was getting him in Amphur building at same time. But had all paperwork already from Marriage and didnt need any extra except copy of latest visa (keep everybit of paper you never know when you need it) Get your pink ID card at same time. Lots of people say its useless, i use it quite a lot just been travelling up north, even got for first time Thai price into national park