Options to consider
There are 47 Alpine or Dual patrollers out of which 19 are rookies. Each year, a few patrollers cannot attend the whole season due to unexpected family commitments, injuries or the need to move outside of the territory.
3 Teams
The teams alternate on each weekend day per the table below.
Each team is appointed one team leader to communicate with the team and ensure adequate coverage for the team day. One instructor is appointed to each team while keeping in mind it might be hard for them to be there every team day because of other commitment.

4 Teams
The idea with 4 teams is to make the schedule more predictable and consistent. With this system, patrollers know they will be at the hill once every 2 weeks on a specific day, either Saturday or Sunday. Just like the 3 Teams system, each team would have a Team Leader to manage communication and foster team spirit.
Everyone in the team would be expected to come on their their team day. A small number of “unavailable” days would be allowed for emergencies or health related issues without penalty. To meet the 10-days commitment, one would have to patrol on a weekday or holiday.
Considering the number of Alpine patrollers and the irregular work schedule of some, there would be roughly 10 patrollers per team at the start of the season. The number is expected to get slightly lower as the season progresses reaching the maximum of 8 patrollers per day.
SIGNUP AHEAD OF TIME
With this system, the roster would be open and patrollers would signup in advance for the days they want to patrol. They would chose at least 10 patrol days spreading them throughout the season. Each patrol day would be capped to a certain number of volunteers per category (fully certified, rookies, instructors) and only the days when one is signed up for would count toward the commitment. If a patroller cannot make one of their commited day, they are responsible for finding someone to cover for them.