Our Elk River supply trips are now down to a fine art. Each push trip requires two or three resupply trips – removing the empty tanks from the previous exploration, taking in full tanks, plus caching other gear as required. We are now using a lot of carbon fibres tanks for the longest swim through sump 7. The carbon fibres are much, much lighter than equivalent steel or aluminium tanks and can hold higher pressures. The drawback of the carbon fibre tanks is their buoyancy characteristics in the water.We have placed kilos of lead weights at the diving gear up spot. Each 9L tank takes 6kgs of lead to sink it. We are definitely not carrying this lead backwards and forwards. [read more…]
