A sloop is the smallest type of ship which has a maximum depth of 250ft. A sloop can be constructed in any of the three continental styles, Thestran, Kojani, or Qalian. A sloop moves at 300% movement speed at full sail.
The Caravel is a medium sized sailing vessel that can be crafted in Vanguard (like the Sloop in all three continental styles). Depth restictions of 600ft., but since there are not much of those deep spots they are free to nearly go anywhere and they are small enough to be used on larger inland rivers and small lakes. They can use "Sea Portals" to sail between continents.
The Galleons are the largest sailing vessels that can be crafted in Vanguard (like the Sloop in all three continental styles). They have no depth restrictions but their size can make it difficult to navigate in tight areas and impossible to sail on rivers or inland lakes. They can use "Sea Portals" to move between continents.