Some captains prefer to approve booking requests manually to ensure they have all the information they need before confirming a trip.
Once you submit a booking request, the captain will have 24 hours to reply. If your trip is due to take place within 24 hours, the captain will be able to reply until the departure time. Captains usually reply within a couple of hours.
If your captain doesn't respond within 24 hours, the request will expire. You will receive an email to confirm the declined booking request with a list of other charters in the area that you can book for your date(s).
Note: If you book a trip that has the 
sign, your request will be confirmed immediately. To find out more about Instant Book, read this article.