An arrangement for a marine vessel, the arrangement comprising: a seat comprising a through hole and adapted to be attached to a hull of the vessel such that the through hole of the seat is aligned with a through hole of the hull, and an electronic device suitable for being fitted to the hull of the vessel, the electronic device being adapted to be attached to the seat, the electronic device further comprising: a transducer adapted to generate a signal to be transmitted into the water outside the hull, and a housing encapsulating the transducer and having a lower portion adapted to be inserted in the through hole of the seat and a flange portion adapted to be attached to the seat so as to support the lower portion in the through hole of the seat, wherein the lower portion and at least the portion of the flange portion located closest to the lower portion have a surface of a material being watertight and transparent to the signal generated by the transducer, and wherein a portion of the surface forms a window of the housing arranged to transmit the signal generated by the transducer to the water outside the hull, further characterised in that the arrangement comprises a gasket adapted to be fitted between the flange portion and the seat for preventing water leakage between the housing and the seat, wherein the arrangement further comprises a plurality of bolts and wherein the flange portion is configured to be fastened to the seat by means of the bolts extending through the flange portion and into the seat. a seat comprising a through hole and adapted to be attached to a hull of the vessel such that the through hole of the seat is aligned with a through hole of the hull, and an electronic device suitable for being fitted to the hull of the vessel, the electronic device being adapted to be attached to the seat, the electronic device further comprising: a transducer adapted to generate a signal to be transmitted into the water outside the hull, and a housing encapsulating the transducer and having a lower portion adapted to be inserted in the through hole of the seat and a flange portion adapted to be attached to the seat so as to support the lower portion in the through hole of the seat, wherein the lower portion and at least the portion of the flange portion located closest to the lower portion have a surface of a material being watertight and transparent to the signal generated by the transducer, and wherein a portion of the surface forms a window of the housing arranged to transmit the signal generated by the transducer to the water outside the hull, further characterised in that the arrangement comprises a gasket adapted to be fitted between the flange portion and the seat for preventing water leakage between the housing and the seat, wherein the arrangement further comprises a plurality of bolts and wherein the flange portion is configured to be fastened to the seat by means of the bolts extending through the flange portion and into the seat. a transducer adapted to generate a signal to be transmitted into the water outside the hull, and a housing encapsulating the transducer and having a lower portion adapted to be inserted in the through hole of the seat and a flange portion adapted to be attached to the seat so as to support the lower portion in the through hole of the seat, wherein the lower portion and at least the portion of the flange portion located closest to the lower portion have a surface of a material being watertight and transparent to the signal generated by the transducer, and wherein a portion of the surface forms a window of the housing arranged to transmit the signal generated by the transducer to the water outside the hull, further characterised in that the arrangement comprises a gasket adapted to be fitted between the flange portion and the seat for preventing water leakage between the housing and the seat, wherein the arrangement further comprises a plurality of bolts and wherein the flange portion is configured to be fastened to the seat by means of the bolts extending through the flange portion and into the seat.