An ultrasonic system for treating a submerged surface of a target structure, the system including: an ultrasonic generator for generating electrical energy to drive first and second ultrasonic transducers, the electrical energy including at least two different frequencies including a first and second operation frequency; first ultrasonic transducers configured to be mounted as a first array to the target structure, and connectable to the ultrasonic generator and operable to generate a first ultrasound signal from the first operation frequency; and second ultrasonic transducers configured to be mounted as a second array to the target structure, and connectable to the ultrasonic generator and operable to generate a second ultrasound signal from the second operation frequency, wherein the first and second ultrasonic transducers are spaceable from one another to produce guided ultrasonic waveforms through the target structure including heterodyned frequencies from the first ultrasound signal and the second ultrasound signal.

A method of controlling an anti-fouling system, the method comprising: activating at least one transducer and at least one sensor; analyzing the at least one transducer and the at least one sensor to determine a set of features of the at least one transducer and the at least one sensor which are controllable; generating a user interface, wherein the user interface is based on the set of features of the at least one transducer and the at least one sensor; generating a sound wave from the at least one transducer based on input data; monitoring the performance of the transducer by collecting data from the at least one sensor; and providing the collected data through the user interface, wherein values outside of a predetermined range, further comprise, transmitting an indicator of the values.

A method of preventing fouling of a submerged structure, the method comprising: activating, by one or more computing devices, at least one transducer and at least one sensor attached to a structure; monitoring, by one or more computing devices, data collected by the at least one sensor related to the submerged structure and the salinity of the water; generating, by one or more computing devices, a predetermined sound wave from the at least one transducer based on the data collected by the at least one sensor; altering, by one or more computing devices, the at least one transducer based collected data from the at least one sensor; and autonomously adjusting, by one or more computing devices, at least one of the at least one transducer.

A method of preventing fouling of a submerged structure, the method comprising: activating, by one or more computing devices, at least one transducer and at least one sensor attached to a structure; monitoring, by one or more computing devices, data collected by the at least one sensor related to the submerged structure and the salinity of the water; generating, by one or more computing devices, a predetermined sound wave from the at least one transducer based on the data collected by the at least one sensor; altering, by one or more computing devices, the at least one transducer based collected data from the at least one sensor; and autonomously adjusting, by one or more computing devices, at least one of the at least one transducer.

A bio-fouling transducer comprising: a housing comprising: a diaphragm a conduit attached to the diaphragm; and a cap attached to the conduit; a transducer element attached to the diaphragm within the conduit; a series of electrical connections electrically connected to the transducer; and at least one gasket attached to the transducer and in contact with the conduit.

A bio-fouling transducer comprising: a housing comprising: a diaphragm a conduit attached to the diaphragm; and a cap attached to the conduit; a transducer element attached to the diaphragm within the conduit; a series of electrical connections electrically connected to the transducer; and at least one gasket attached to the transducer and in contact with the conduit.

A method of autonomously preventing fouling of a submerged vessel, the method comprising: activating, by one or more computing devices, a at least one transducer and at least one sensor at a first area; generating, by one or more computing devices, a predetermined sound wave from the at least one transducer; monitoring, by one or more computing devices, data collected by the at least one sensor; altering, by one or more computing devices, the at least one transducer, wherein the alteration is based on the data collected by the at least one sensor; and autonomously adjusting, by one or more computing devices, at least one of the at least one transducer, wherein at least one of the transducers is activated.

Method performed by a first communication device (101) operating in a wireless communications network (100). The first communication device (101) obtains (201) a first set of one or more values indicating an observed speed of a boat (151) relative to a power of an engine (161) of the boat (151). The speed and the first indication are obtained by from sensors (171, 172) in the boat (151). The first communication device (101) then obtains (205) a second indication of an external factor on the hull of the boat (151) causing friction against water. The obtaining (205) of the second indication is based at least on: the obtained first set, and a reference. The reference is based on one of: a) a threshold, and b) a mathematical model. The first communication device (101) also initiates providing (206) a third indication of the external factor to a device (103), based on the obtained second indication.

A drainage device for directing fluid away from a thru-hull fitting located on a hull of a vessel includes: a channel body mountable proximate to and extendable away from the hull of the vessel; a groove formed along at least a partial length of the thru-hull body; and a lip protruding from a bottom edge of the channel body at an end of the channel body that is distal from the hull of the vessel when the drainage device is mounted thereon.

An electric current supply system (20) is designed to be at least partially submerged in an electrically conductive liquid during operation thereof, and having at least one electrically conductive component (21, 22, 23, 24) enveloped in liquid-tight material (40). The component (21, 22, 23, 24) has a sacrificial material that is capable of reacting electrochemically with the liquid. Further, the component (21, 22, 23, 24) has at least one gas trap portion (50) at which the sacrificial material occupies a space in the liquid-tight material (40) that is thereby defined with a gas trapping shape. If, in case of damage to the system (20) in an actual submerged state thereof, the component (21, 22, 23, 24) gets exposed to the liquid, it is achieved that an electrochemical reaction occurring at the exposed area of the component (21, 22, 23, 24) and an outflow of electric current to the liquid are stopped.