DESCENT X50i Owner’s Manual

Dive Planning

You can plan for future dives using your dive computer, such as calculating your breathing gas or no-decompression limit (NDL) times.

Calculating NDL Time

You can calculate the no-decompression limit (NDL) time or maximum depth for a future dive. These calculations are not saved or applied to your next dive.

  1. Select Plan Dive > Compute NDL.
  2. Select an option:
    • To calculate NDL based on your current tissue load, select Diving Now.
    • To calculate NDL based on your tissue load at a future time, select Enter Surf. Interval, and enter yoursurface interval time.
  3. Enter an oxygen percentage.
  4. Select an option:
    • To calculate the NDL time, select Enter Depth, and enter the planned depth for your dive.
    • To calculate the maximum depth, select Enter Time, and enter your planned dive time.

The NDL countdown clock, depth, and maximum operating depth (MOD) appear.

NOTE: If the planned depth exceeds the MOD of the dive computer or the breathing gas, the planned depth appears in red.

  1. Press ENTER.
  2. Select an option:
    • To exit, select Done.
    • To add intervals to your dive, select Add Repeat Dive, and follow the on-screen instructions.

Calculating Your Breathing Gas

You can calculate the PO2 value, oxygen percentage, or maximum depth for a dive by adjusting two of the three values. The calculations are affected by the water type setting in the Dive Setup menu (Dive Setup).

  1. Select Plan Dive > Calculate Gas.
  2. Press PREV or NEXT, and select an option to calculate:
    • Select PO2.
    • Select O2%.
    • Select Depth.
  3. Press PREV or NEXT to edit the first value.
  4. Press ENTER, then press PREV or NEXT to edit the second value.

As you edit the values, the device calculates an adjusted value for the highlighted option.

  1. If necessary, press BACK to calculate the value for a different option.

Creating a Decompression Plan

You can create open-circuit decompression plans and save them for future dives.

  1. Select Plan Dive > Deco Plans > Add New.
  2. Enter a name for the decompression plan.
  3. Select an option:
    • To enter the maximum partial pressure of oxygen in bars, select PO2.

    NOTE: The dive computer uses the PO2 value for gas switching.

    • To enter your level of conservatism for decompression calculations, select Conservatism.
    • To enter your gas blends, select Gases.
    • To enter the depth of your last decompression stop, select Last Deco Stop.
    • To enter the maximum dive depth, select Bottom Depth.
    • To enter the time at the bottom depth, select Bottom Time.
  4. Select Save.

Using Decompression Plans

  1. Select Plan Dive > Deco Plans.
  2. Select a decompression plan.
  3. Select an option:
    • To view the decompression plan, select View.
    • To use the decompression plan settings for a dive mode, select Apply.
    • To change the decompression plan details, select Edit.
    • To edit the name of the decompression plan, select Rename.
    • To remove the decompression plan, select Delete > Yes.