An orientation apparatus for swimming, comprising: an attachment unit for attaching the apparatus to a swimmer; a user interface element; at least one processor and at least one memory including computer program code (PROG), wherein the at least one memory and the computer program code (PROG) are configured, with the at least one processor, to cause the apparatus to perform operations comprising: obtaining heading information indicating a target heading to a target; detecting, during swimming, that the swimmer deviates from the target heading; and informing the swimmer, via the user interface element, that the swimmer has deviated from the target heading; characterized in that the orientation apparatus further comprises: an inertial measurement unit; wherein the at least one memory and the computer program code (PROG) are configured, with the at least one processor, to cause the apparatus to further perform operations comprising: detecting that the swimmer starts swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically starting to check whether the swimmer has deviated from the target heading; and detecting that the swimmer stops swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically stopping to check whether the swimmer has deviated from the target heading. an attachment unit for attaching the apparatus to a swimmer; a user interface element; at least one processor and at least one memory including computer program code (PROG), wherein the at least one memory and the computer program code (PROG) are configured, with the at least one processor, to cause the apparatus to perform operations comprising: obtaining heading information indicating a target heading to a target; detecting, during swimming, that the swimmer deviates from the target heading; and informing the swimmer, via the user interface element, that the swimmer has deviated from the target heading; characterized in that the orientation apparatus further comprises: an inertial measurement unit; wherein the at least one memory and the computer program code (PROG) are configured, with the at least one processor, to cause the apparatus to further perform operations comprising: detecting that the swimmer starts swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically starting to check whether the swimmer has deviated from the target heading; and detecting that the swimmer stops swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically stopping to check whether the swimmer has deviated from the target heading. obtaining heading information indicating a target heading to a target; detecting, during swimming, that the swimmer deviates from the target heading; and informing the swimmer, via the user interface element, that the swimmer has deviated from the target heading; characterized in that the orientation apparatus further comprises: an inertial measurement unit; wherein the at least one memory and the computer program code (PROG) are configured, with the at least one processor, to cause the apparatus to further perform operations comprising: detecting that the swimmer starts swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically starting to check whether the swimmer has deviated from the target heading; and detecting that the swimmer stops swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically stopping to check whether the swimmer has deviated from the target heading. an inertial measurement unit; wherein the at least one memory and the computer program code (PROG) are configured, with the at least one processor, to cause the apparatus to further perform operations comprising: detecting that the swimmer starts swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically starting to check whether the swimmer has deviated from the target heading; and detecting that the swimmer stops swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically stopping to check whether the swimmer has deviated from the target heading. detecting that the swimmer starts swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically starting to check whether the swimmer has deviated from the target heading; and detecting that the swimmer stops swimming by detecting movements of the orientation apparatus using the inertial measurement unit, and therefore automatically stopping to check whether the swimmer has deviated from the target heading.