You should expect your coordinator to get in touch at at least 48hrs ahead of sample collection date. He/She may request for some credentials eg. Passport Details to pass on to vessel agent to help arrange port passes for you.
As you are already aware, maritime industry can be very agile and it is foreseeable that some requests may be impromptu or incident driven which may require a shorter notice time. Thisnotwithstanding, we do expect a reasonable notice time as this will also be needed to get adequate logistics prepared for a collection site and date.