A ground anchor can be very handy for solo launching and landing of a kiteboarding kite. In a pinch you can improvise with your safety leash around a fixed object, but that impairs a safety system and requires a solid object in the right place. I put this anchor together from a retired rock climbing sling, some corrugated drain pipe, and a pet anchor. Some sort of protection is critical because you don't want a sharp and pointy steel object knocking around in your trunk or on the beach around kites and boards!
This link will almost certainly break, but the anchor is a Tractor Supply SKU 2436087 Retriever® Tie Out Stake with Auger, coming in at 24" in length and about $20 USD.