1. Spools and reels can be used however you want. There's no law against using a spool for laying down primary line. Generally, though, large reels have a lot of line and are used for primary navigation lines. Small reels or spools can be used for backup (emergency). But as I said, if I'm in an emergency I don't want to have to worry about a jammed reel or a reel that falls apart (had it happen once).
2. You don't need tie off with a spool just because you're practicing.
3. I have thigh pockets sewn to my drysuit and glued to my wetsuit.
4. Each cavern/cave is different. Many of the more popular caverns have a permanent cavern lines established that circle the cavern. You'll need to run a guideline from open water to the cavern guideline. (A permanent line from open water to the caven line would encourage open-water divers to enter the cavern.)
5. The velcro idea is interesting but is not part of the current dogma of cavern/cave diving. Considered a gear solution to a skills problem.
The red reel shown above jams too easily for my taste. mine is relegated to dive flag float duty.
2. You don't need tie off with a spool just because you're practicing.
3. I have thigh pockets sewn to my drysuit and glued to my wetsuit.
4. Each cavern/cave is different. Many of the more popular caverns have a permanent cavern lines established that circle the cavern. You'll need to run a guideline from open water to the cavern guideline. (A permanent line from open water to the caven line would encourage open-water divers to enter the cavern.)
5. The velcro idea is interesting but is not part of the current dogma of cavern/cave diving. Considered a gear solution to a skills problem.
The red reel shown above jams too easily for my taste. mine is relegated to dive flag float duty.