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Post: Hello Slawek The main advantage the 1 Wire Pi Zero has over the default RPi GPIO based 1-wire bus is that the 1 Wire Pi Zero uses a 5V 1-wire bus while the RPi-based network will be running at 3.3V. A higher voltage gives better performance on long 1-wire networks. Maxim has a good tutorial on designing reliable 1-wire networks, you can find it at [url=https://pdfserv.maximintegrated.com/en/an/AN148.pdf]AN148[/url] The other main benefits of the 1 Wire Pi Zero are the built-in ESD protection using a DS9503 protection diode and the ability to stack up to 4 boards on the Raspberry Pi while only using the two I2C pins, reducing the number of GPIO pins needed. The DS9503 protection diode on the 1 Wire Pi Zero should give you more protection against EM spikes compared to connecting the 1-wire network directly to the Raspberry Pi GPIO pins. The DS9503 won't help if lightning strikes directly or close to the 1-wire cable but it should reduce the risk of damage from currents induced on the cable by nearby strikes. A screened cable will help reduce the effects of lightning. You only want to ground the cable screen at the Raspberry Pi end of the cable. It is not generally recommended to ground screened cables at both ends as this can increase the risk of damage from lightning as a nearby strike can cause a voltage difference in the ground at each end of the cable which will induce a voltage on the inner cores. Do you get many big waves or choppy water in your marina? If you have a row of reed switches in a pipe with loops of wire running down the inside and a strong neodymium magnet on the outside that moves up and down you have basically created a generator. If the float is moved up and down rapidly in rough weather that could induce voltage spikes on the sensor wires. You may want to add Zener diodes across the wires before they connect to the DS2438 to reduce the chance of damage from spikes caused by the magnets.