
White rum is a light, mild molasses rum, bottled clear and often charcoal-filtered, in the Spanish-Caribbean "ron ligero" style. It is not neutral: a soft cane character stays under the lightness.
Gold or aged rum
Comes closest, in the same amount. It tints the drink and adds vanilla and oak.
Goes in at about two-thirds of the measure. The drink tastes of it.
Rhum agricole blanc or cachaça
Grassier and bolder, and the drink tastes of them.
"White rum is basically rum-flavored vodka"
All they share is that both are clear. In a Daiquiri you taste the rum; vodka in its place just leaves the drink sour and strong.
The molasses ferments short and clean, unlike the longer ferments behind many Jamaican rums. It comes off a column still at high strength, which is where the lightness comes from.
At 37.5–40% nothing in the bottle spoils. What does fade, slowly, is the faint cane sweetness that separates a good white rum from neutral alcohol. It fades faster once the bottle is more air than rum, so decant the last third.
Mai Tai (Beaumont-Gantt's)
Jamaican-style overproof aged rum