I've been on several HAL charters.
For full ship charters, the group rents out the ship. Due to this, they create the prices and tickets are not sold directly on the HAL site. Due to not being a 'HAL cruise' no surveys are sent out and future cruises is not offered. The charter sets up thier own future cruise, for guests to rebook. Many ship policies are bended to match what the organizers want.