(1) The hidden underlying reference to squareness, and boat-like shape, of the heads on Singaporeans (originally designed by the Merry Boat Heads clan as a way to insult without having to face the penalties/risks of being "offensive").
(2) It also can be referenced to the greatest gaming clan in Singapore - the notorious Merry Boat Heads.
Being insulted as a boathead is probably the worst thing you can imagine - yet each member of the Merry Boat Heads is, ironically, able to be compared to that of a God; they are each that amazing.
(3) It's a professional troll word - used by only the masters.
You're a boathead!
Don't worry; The Merry Boat-Heads crushed you - it's expected since the start!
Boathead!
24π 8π
A common nickname for the largest headed mammal on the planet, only qualifying if its head to body ratio surpasses 18:1. Typical characteristics of a Boathead include poor dress sense, being sensitive, needy and a generally unpleasant individual.
Greg: βIs that a hot air balloon floating towards us in the distance?β
John: βNo, itβs just Boathead going for his morning strollβ