How early should a Thunder Bay engineer apply before a January lay-up start?

Close to the start, once the operator can state what the season contains. Because admission is decided on arrival and the period granted is tied to the employment described, applying against a schedule that has not settled produces either a refusal or an authorization that no longer matches the work.

Apply to the season you can document, not the one you hope for

A lay-up plan firms up late, usually when the fleet's last cargo is discharged and the docking list is finalized. Eero should treat that moment, rather than the calendar, as the trigger to finalize his letter. Three answers should hold still before he sets out: what he will work on first, when the yard expects him, and how long the operator now expects the assignment to run.

Two traps recur in the interval. Beginning drawings or specifications for the American operator from Thunder Bay while waiting raises questions about when the employment started and who authorized it. Crossing early as a visitor to attend planning meetings, then staying to perform productive engineering work, is a different problem with worse consequences.

Neither should be improvised without advice, and neither is fixed by a later letter.