Calculating minimum surface intervals is an essential skill for divers operating within logistical confines, wanting to make the most out of their diving day.
Take your PADI RDP and calculate the pressure group designation for the first dive using Table 1.
Now flip your RDP over to find Table 3 - find where the depth intersects closest with the adjusted NDL and then follow the table up to find the required pressure group designation.
Now use the table in reverse by taking the pressure group designation from Table 3 and intersecting it with the pressure group designation in Table 1 in Table 2.
This will give you the minimum surface interval required by the PADI RDP.