Transporting Equipment Through Sumps
Transporting Items through Sumps can be a challenging task. As modern day exploration continues to advance, in both training and equipment, further objectives are coming into focus. Sumps once an obstacle that stopped early explorers are now being dove at an increasing rate with objectives being climbs, pits, or even further sumps. These objectives and projects are now requiring camps, electronics, and battery operated equipment to be transported through underwater sections of caves (sumps) dry in order for them to work properly. Below are a few ideas, considerations and tools for doing just that. Remember cave diving kills.
1. Wet vs Dry
Can the equipment in question be transported through the sump wet?
It is much simpler to transport equipment through sumps wet, than it is to transport them dry.
Equipment like therm-a-rests (neo air), camp fuel, stoves, pots, tarps, bolts, hammers, rope etc can be transported wet.
Sleeping bags, food, hammer drills, batteries, camera equipment, sensitive survey equipment etc needs to be transported through sumps dry in order not to destroy the equipment maintaining its functionality.
2. Fixed Volume vs Variable Volume Containers
Fixed volume (non compressible ie. Nalgene bottle) containers have the advantage of knowing the exact weight required to make neutral buoyant and having no changes in buoyancy characteristics with depth variations within its operating range. The weights required to make neutral can be placed inside or outside (increasing drag) of the container.
Variable volume (compressible ie. Dry bags) containers can be rolled up and compressed for transport when not needed. However the amount of weight required to make neutral will vary and the bags buoyancy characteristics will vary with depth changes within the sump, adding to the task loading of the dive. Be careful you could have a disastrous event with the buoyancy issues of the variable volume containers.
Choose wisely which method suits your needs.
Finding premade containers that are reliable and cheap can be difficult. Test your chosen method in a safe environment with non-valuable objects to assure its practicality before taking it underground.
If you go to an army surplus store they may have some old used rocket tube containers kicking around. Check that they are not cracked, and the o-rings are in good repair. They can usually be used to depths of -20m or so to transport small items through rough sumps. They can be transported in a bag or attached to you similarly to stage bottles.
You can order Nalgene bottles in 1/2 L, 1L, 2L, and 4L sizes. Stick to the wide mouth variety as this will give you more options as to what you place in them. Avoid old brittle or cracked bottles. Good to -30m.
These have gained popularity with "dry" cavers to store personal items in muddy, wet caves. They can also be utilized in shallow sumps if sealed correctly. Good to -10m these are available at many caving equipment suppliers.
A heavy method to transport hammer drills etc through sumps is by using old ammo boxes. These are not the best method, but if you do not have time or money they can do the job. Good to -20m.
Double bagging equipment in dry bags can work in very short shallow sumps. Be sure to squeeze all of the air out of the bags and avoid going deeper than -3m and make it quick.
A do it yourself project! Acquire an car inner tube from the local tyre shops scrap heap. Seal and secure one end permanently with zip ties and snoopy loops. Seal the other end with snoopy loops after carefully folding and rolling it up. It is strongly suggested that you place your equipment in a plastic bag or dry bag prior to the Pig. Remember to test your Pig first before committing expensive equipment. Good to -20m.
Dive dry bags
Some dive companies and Do It Yourselfers create a waterproof bag then use a drysuit zipper to act as the closure system. While generally reliable, plan for buoyancy issues. Good to -20m or so.
If you are carrying your dry container in a cave bag be careful of putting rocks and lead into the cave bags as these can fall out during the dive causing many problems from buoyancy issues to a diver being injured from the lead hitting them in the head etc. Lace the top of the bag well or use something different.
Please remember you will design your systems for the environment in which you are working. As an example the equipment in the photos was being used in winter to dive a 2 degree Celcius sump, that is why I used carabiners. One system will never work everywhere or for everything. Keep your mind and eyes open for new solutions and ideas. Try to keep it light and remember to KISS, KISS (Keep it simple stupid, Keep it safe stupid).