In the newer waypoint management software version ...there is an option to hide the waypoints ... But I'm not sure that your 997 has new enough software to have the waypoint management feature ...
Look under the Chart tab for Waypoints ...
*Cursor down to Waypoints
*Cursor right ...
If the waypoint management window opens you can choose to hide the waypoints in there ...
If only option to Create, Edit, Delete, GOTO show up ...check in the Edit submenu ...
If there's not an option there to hide the waypoints ...you can still export the waypoints from the unit internal memory to a SD Card, delete the waypoints from the internal memory ... And re-install them later ...
Rickie