Abstract: A new device including a new arrangement of dive tables is disclosed for planning non-decompression dives. The invention utilizes two separate scales, movable relative to one another. The first scale shows the pressure group scale, the bottom time or residual nitrogen scale and surface intervals aligned by relationship to pressure group. The second scale shows depth scales, repetitive dive group, pressure group, and no decompression time limits scale. Windows in the second scale allow the observation of pressure group scales and corresponding bottom time on alignment of bottom time from scale one with depth from the second scale.