| -> | | | | reached, it continually computes the theoretical |
| Traditionally recreational scuba divers have carried a | | | | nitrogen absorbed by different parts of the body. |
| depth gauge, dive watch and dive tables to dive to a | | | | This means that although a maximum depth of 30 |
| plan, but the advent of low-cost computers designed | | | | metres may be reached during the dive, if much of |
| to monitor depth and time on a second to second | | | | the dive is at a shallower depth then the body's |
| basis means that divers can now have longer dives, | | | | absorption of nitrogen will be much less than that |
| and if correctly used, stand much less chance of | | | | assumed by the dive table. |
| suffering a diving related injury. | | | | To return to the example of a 42 metre (140 feet) |
| The way in which divers using the standard tables | | | | dive, which gives a maximum bottom time of 10 |
| dive, compared with how divers using a dive | | | | minutes if diving to the limit of the table, I'd like show |
| computer is slightly, but significantly different, due to | | | | how a real dive to the same depth using a computer |
| the fact that in the former the whole dive is planned | | | | can give a much longer dive time. My deepest dive |
| on the maximum depth reached. | | | | last summer was in Cap de Creus (Costa Brava, |
| For example, using the PADI tables to dive to 30 | | | | Spain), to a depth of 42.1 metres according to my |
| metres (100 feet) the no-decompression time is 25 | | | | computer. |
| minutes. That means that the total time from | | | | The maximum depth was reached nearly nine |
| starting the decent to the point at which ascent | | | | minutes into the dive and I remained at that depth |
| begins can be no longer than 25 minutes, and at 42 | | | | for about two minutes and then ascended slowly to |
| metres (140 feet) the no-decompression time is just | | | | about 30 metres for 5 minutes. Slowly ascending |
| 10 minutes - considering that you are always advised | | | | again, much of the remainder of the dive was |
| to dive conservatively and so not to the limits of the | | | | completed at a depth of 15 metres, before ascending |
| tables in reality your dives would be even shorter. | | | | to 5 metres for a safety stop and then breaking the |
| However a dive computer works differently. Rather | | | | surface, a total dive time of 45 minutes. |
| than base the dive time on the maximum depth | | | | |