If you are looking to do your Open Water course it might be an idea to learn in Thailand first. It is cheaper, easier conditions and generally more convenient. If you really do want to do the Open Water course on a Myanmar Liveaboard, you should try and complete the theory and confined sessions before departure.
A Myanmar liveaboard is a great environment for more advanced courses. The Nitrox and Advanced Open Water courses are almost essential for you to make the most of your diving holiday. You can learn both these courses on the boat and they will greatly improve your Myanmar diving options.
A liveaboard is the perfect classroom environment for learning to dive. A liveaboard gives you ample time to study, practice and spend plenty of hours in the water honing your diving skills. Diving courses on a liveaboard are always conducted at a much more relaxed pace.
There is less pressure to complete tasks in a limited amount of time. You will have plenty of free time to enjoy the Mergui Archipelago. Should one or two skills require extra practice, do not worry. On a Myanmar Liveaboard you are constantly surrounded by the Ocean. Jumping in for more practice is always an option.