Wa (Thai: วา [wāː], also waa or wah, abbreviated ว.)
is a unit of length, equal to two metres (2 m) or four sok (ศอก.)
Wa as a verb means to outstretch (one's) arms to both sides, which relates to the fathom's distance between the fingertips of a man's outstretched arms.
The 1833 Siamese-American Treaty of Amity and Commerce, reads, "[The] Siamese fathom...being computed to contain 78 English or American inches, corresponding to 96 Siamese inches.
[2] Since conversion to the metric system in 1923,[3][4] the length as derived from the metre is precisely two metres, but the unit is neither part of nor recognized by the modern International metric system (SI).