What is the deposit and how much is it?
A part-payment that confirms your date and takes the boat off the market. The amount varies by trip and is shown in full before you pay anything.
A confirmed booking costs the captain the day. The deposit is what makes that commitment real on both sides — it gives them enough certainty to turn other work away, and it keeps your outlay small until you are actually standing on the dock.
Deposits differ from boat to boat, so there is no single figure. Checkout shows the exact deposit and the exact balance you will owe the captain before you enter any card details.
Paying the whole trip online is not offered here. Captains in this bay collect the balance themselves, and that is how the local charter business works.