Abstract: The invention concerns a method, device and computer program product for monitoring or planning a dive of a diver. The method includes providing data on the composition of gases breathed by the diver during the dive, providing data on the depth or ambient pressure of the diver, and using a model to provide a safe ascent profile for the diver based on the data on the composition of gases and on the depth or ambient pressure. According to the invention, the method further comprising detecting, based on the data on the composition of gases, a gas composition change which may lead to a deep tissue isobaric counter diffusion situation, and the model comprising means for immediately temporally retarding the ascent profile if such gas composition change is detected. The invention can be used to mitigate the harmful effects of dangerous breathing gas changes during diving.

Abstract: A method and an electronic device for determining the direction of a magnetic field, in which a mobile electronic compass device is used to measure three field vectors of the magnetic field the desired number of times. From each measurement, a data point (p1-p6) is formed in a three-dimensional co-ordinate system, for which measured data points a common reference point (C) is calculated. The location of the device is determined relative to the reference point in said co-ordinate system and the co-ordinates of the reference point obtained are compared to the co-ordinates of at least one previous reference point, and the co-ordinate values of the reference point are calibrated, after which the direction of the magnetic field is indicated with the aid of the reference point.

Abstract: The invention concerns a method, device and computer program product for monitoring or planning a dive of a diver. The method includes providing data on the composition of gases breathed by the diver during the dive, providing data on the depth or ambient pressure of the diver, and using a model to provide a safe ascent profile for the diver based on the data on the composition of gases and on the depth or ambient pressure. According to the invention, the method further comprising detecting, based on the data on the composition of gases, a gas composition change which may lead to a deep tissue isobaric counter diffusion situation, and the model comprising means for immediately temporally retarding the ascent profile if such gas composition change is detected. The invention can be used to mitigate the harmful effects of dangerous breathing gas changes during diving.