As a dive instructor I spend quite some time explaining the dive tables to my entry level divers. We work through the numbers and turn slates over and over, doing calculations and drawing profiles until it makes sense.
When I guide fun divers I rarely see anyone use the skills that they worked so hard to figure out. We learn that it is not safe for two divers to share a dive computer and yet many fun divers that I have taken on dives were happy to leave all the responsibility of the planning of their dive to me. In 9 months only a handful of customers ever asked me whether we will stay within the table limits.
Divers seem to forget that a dive guide’s role is to show them the dive site, point out interesting creatures and features and yes, take care of their customers in an emergency situation. Briefings include a standard time and depth limit. These limits should be taken as guidelines and a base for a certified diver to plan his or her individual dive.
Tools to assist you in planning your dive
There is a variety of tools that you can use to assist you to plan your dive. As I mentioned before it includes a timing device as well as a depth gauge.
These can be used in conjunction with any form of recreational dive planner to calculate your personal bottom time and depth limits. For those who find it confusing to struggle through the technicalities of dive tables there are new electronic versions that do all the calculations for you.
Staying within your personal limits
Standard dive equipment should include a timing device as well as a depth gauge and need to be used by divers to control their depth and ensure that they stay within their qualification and no decompression limits. Though a good dive guide should assist divers in planning their own, individual dives, it is the diver’s responsibility to control his or her own depth and duration of the dive.
Although dive guides take their customers’ certification limits into consideration when briefing the general dive plan, customers might be more aware of their personal dive limits and should include these when they plan their dives.
Factors like physical fitness, date of last dive, experience and comfort in the water might influence
Stick to your plan, have a contingency and cancelling dives
When you’ve planned your dive, stay with your planned depth and time. You do not need to go to your limit on every dive, often shallower and even shorter dives are enjoyable with many things to see.
The temptation to stray from your plan could be big, especially if you spot a unique creature hiding a few meters deeper than the depth that you had planned. It is a good idea to have a contingency plan to cater for this by selecting your depth to be a few meters shallower than your absolute maximum, dictated by your certification level.
Remember that although diving is fun, your safety and those around you comes first. Thus it might be wise to return to a shallower depth, or even cut your dive short, if you find yourself in unsafe or under strenuous conditions. Rather return to the site in better conditions which would offer you a more enjoyable, and perhaps memorable, dive.
*A version of this article first appeared at www.scubadiverlife.com