File:Special Duration Up Chart.png

Formulas
x = Ability Points = 10*MainSlots+3*SubSlots

Bomb Rush, Bubbler, Inkzooka, Kraken: Duration (s) = [base duration]*(1+(0.99*x-(0.09*x)^2)/50)

Echolocator, Inkstrike, Killer Wail: Duration (s) = [base duration]*(1+(0.99*x-(0.09*x)^2)/75)