The price you see is the all-in price for your dates: the charter, every fee the operator requires (including those you settle at the base, such as a transit log, final cleaning or tourist tax) and the flat €45 platform fee. Optional extras are added only if you choose them. The refundable security deposit is listed apart, because it comes back to you. Each boat lists its fees on its page. The full breakdown: https://charter.boats/fees-and-pricing