Table 3 Parameter values and assumptions.

Incubation period (days), θ

Lognormal distribution with Mean = 4.4, sd  = 1.9

⁵¹

Adherence to isolation when tested positive (%)

100

For scenarios involving testing only and we assume that there are available cabins for individuals to isolate given that cruises are operating at 50% capacity.

Delay from positive test to isolation (hrs)

No delay

For scenarios involving testing, individuals were isolated once tested positive.

Initial cases among passengers

1

Scaling parameter, r_scale

0.24–0.26

Each network formulation uses one scaling parameter value to calibrate the probability of Delta infection among cabin contacts to be similar to that of household contacts of 20%^34,49,52. The range of values used across the different network formulations are as shown.