You just found a 20lbs davenport anchor and can't figure out how you can get this prize back to the surface. You need a lift bag. You never know what you're going to find on a dive that is worth money, so always pack a lift bag when you go diving. XS Scuba offers a 50lb Lift Bags with a unique "anti-spill" bottom with baffle to allow easy fill from any device and prevent lift bag from dumping air or taking on water when it hits the surface
Bag is equipped with over pressure relief valve with pull for manual release of air, has a stainless steel D-ring at top for attachment of a slate, elastic loop at top for attachment of chemical light, and lifting straps with stainless steelD-rings at the bottom. Lift bag rolls up to a compact size and stays closed witha Velcro strap. So don't be caught without one when you go diving. You never know what treasures you may find!