Scooters
You can’t deny it scooters are great fun. I’ve spent many dives buzzing about on a scooter for fun and it’s very enjoyable. For many divers this is as far as it goes; good fun but at the end of the day they are just big boys toys. For the technical diver things are slightly different. In some circumstances a scooter or a diver propulsion vehicle (DPV) become an essential tool.For cave divers a scooter is essential. Many of the deep penetration cave dives would simply be impossible without a scooter. The distances are just too far to swim. In these situations the scooter is en essential part of the diver’s life support system, they would not be able to swim out without it and so spare scooters and scooters staged at certain points are just as important as spare and staged gas. Cave diving scooters require very long burn times and can trade-off increased weight for increased burn time.
For wreck divers a scooter is not part of their life support system but it can still be an essential tool. Deeper wrecks are often larger and more intact than those in shallower water and so there is more wreck to see. At the same time, for deeper dives the available bottom time becomes a critical resource and a scooter allows the diver to see more of the wreck within that bottom time.
A few hours before writing this I was diving on one of the 26,000 ton battleships in Scapa Flow. Without a scooter I would only have been able to cover a fraction of the wreck. With a scooter it is possible to see much more of the wreck and get a much better idea of the orientation. When planning wreck penetration it is useful to dive the outside of the whole wreck and get a full picture of the layout before deciding where and how to penetrate the wreck. If you are swimming around the wreck this may not be possible. Even on quite modest sized wrecks you will only get a limited time to explore the wreck if it lays in 80m. For dives where there is a specific purpose or a specific part of the wreck that the diver wants to see then a scooter can ensure that they can get to that part of the wreck and still have enough time left to explore the area.
Using a scooter has the additional benefit that your breathing rate will be reduced. Once you become familiar with the scooter it takes very little effort as no fining is required and so your breathing rate will drop. For open circuit divers gas consumption is a key part of dive planning and this reduced breathing rate allows additional time on the bottom.
A scooter can also be invaluable when diving a wreck that has strong currents or a very small slack window. When diving on a rarely dived wreck information on slack water may be difficult to obtain. For this reason there are often significant currents. A scooter allows you to dive in conditions that would be impossible for a free swimming diver. It may be too difficult to swim against a current and even if possible the current will have a significant impact on your breathing rate and hence gas consumption.
For wreck diving the type of scooter required is lighter than a cave diving scooter as you need to be able to jump in from a boat with it. Long burn times are not as important as for a cave diving scooter as the dive durations and distances travelled are much shorter. A wreck diving scooter should also be rugged enough to withstand the stress of being onboard a pitching boat.
It is possible to buy a scooter for under £100 but these are not suitable for technical diving. They tend to have a very limited depth rating and do not have sufficient power to pull a twinset diver equipped with multiple stages. The technical diver needs a scooter that is depth rated to at least 100m and has sufficient power to full them and all their equipment.
Have fun and dive safe
Mark
http://www.dive-tech.co.uk
http://www.divingniknaks.com