Why Deck Cameras Go Blind: Salt, Soot and the Wiper Washer Pair

Three kinds of fouling

Water on the glass is the easy case: a wiper clears it and the picture comes back. Salt is different — it dries into a film that scatters light, and a wiper dragged across a dry salt film scratches the coating instead of cleaning it. Soot from a funnel uptake is worse still: it is oily, it adheres, and it builds up in layers.

Which means the maintenance question is never "is there a wiper" but "what is on the glass, and what clears it".

What a wiper does, and does not do

In this range the wiper is fitted to the PTZ and bullet families, and it is listed in the model name because it is the reason those models exist. It sweeps the window in front of the lens — a mechanical solution to liquid water.

It does not dissolve salt, and it cannot remove a film that has already dried. Wiping a dry, salted window is the classic way to turn a slightly hazy picture into a permanently scratched one.

What the washer adds

The washer tank carries its own water: a 5 L reservoir, a vacuum pump at 27 PSI, more than 1.9 litres a minute through a 5 m polyethylene hose, from the vessel 12 V supply at 10 W. The intended sequence is spray, then wipe — wet the film, then let the blade move it off.

That is why the two are specified as a pair on vessels where fouling is heavy. Neither is expensive; the cost of not having them is a camera nobody trusts, and eventually a crew that stops looking at the screen.

Sizing the routine

A 5 L reservoir at just over 1.9 L/min is built for bursts, not continuous spraying — a few seconds before each wipe cycle, which is how a vehicle washer works and how a deck camera should be cleaned. Refilling is a scheduled maintenance item, and on a long passage it is worth treating as one rather than discovering it when the picture goes white.

When a dome changes the answer

Domes have no wiper in this range, and their curved window collects film faster than a flat one. That makes the cleaning routine more important, not less: a dome on an exposed deck needs either the washer or a documented manual clean, decided while the mounting position is still being chosen.