V-Planner is a diving decompression program that uses the Varying Permeability Model (VPM-B) for decompression profiles.
V-Planner is a decompression program that uses the Varying Permeability Model (VPM-B) for decompression profiles. The VPM-B decompression model is well suited to today's technical diving. The deco profiles will start deeper than traditional models, accounting for micro bubble growth and controlling this, giving a better overall decompression.
Bubble models and similar deep stop profiles, have become the standard for technical and deep diving, with many training agencies including bubble models into thier courses. The VPM bubble model uses math to simulate and measure micro bubble growth, and set limits accordingly. The output of a bubble model is remarkably similar to many established deep practices such as Pyle Stops, Pearl divers, Florida cave practices and others. At the recent Deep Stops Workshop, presentations from Comex and USN researchers among others, showed that the bubble model style profile is the preferred approach to decompression.
In VPM, ascent ceilings are determined on allowable gradients for bubble formation rather than M-values. These super saturation gradients are determined by tracking sets of VPM nuclei (bubble seeds) of a certain initial critical radius. These are the microscopic physical structures that stabilize free phase gas and that can grow into full fledged bubbles when the super saturation gradient is sufficient to probe the laplace condition for bubble formation.