A diver of Residual Group E at the time of the first diving end plans the second diving of 35 minutes at 15 m in a coral reef.How long Surface Interval Time is necessary at least?

《The usage of Dive Table》

① You should look for Residual Group E at the time of the first diving end in <Table 2> Surface Interval Time Table
② You should look for 15m for the next diving in the depth(D) of <Table 3> No-decompression Dive Limit - Residual Nitrogen Time Table.You just trace aside from 15m and look for No-decompression Dive Limit that is 35 minutes or over 35 minutes and closer to 35 minutes.
③ The contact of the point traced No-decompression Dive Limit 51 minutes in above and the point traced Residual Group E aside ② is between 1:00 and 2:00.

a) Planned depth of the next diving  b) No-decompression Dive Limit

Correct answer： Surface Interval Time after one hour

If you have 1 hour Surface Interval Time at least, you can dive for 35 minutes at 15m for the second diving.