Answer is same, it's not possible that communication devices stop working every day in every ship. If you even claim that it is possible in every day and every ship then please, try to explain how.
Simple. Communication devices are known to fail from time to time; all that would be needed is for all the devices on board the ship to fail between leaving port and sinking.
OP isn't about people who observe "sinking" ships daily.
The OP is talking about the phenomenon of ships appearing to disappear below the surface of the water. That sounds like sinking to me.
And your claim about that is still wrong.
Please justify this statement.
What evidence?
The people that observe ships to sink in this way daily.
And the sinking of the ships is quite well explained and the thing is they don't seem that way that they are actually sinking. You better explain your reasoning behind the ships sinking. Because if you see the ship disappearing doesn't mean that it is sinking. That's not how science works.
Please don't try to pin the blame of jumping to conclusions on me; I'm only pointing out that this is a possibility that needs to be considered. You are the one jumping to the conclusion that the Earth must be round -- what is more likely, that the entire Earth is warped just to suit your expectations, or that ships observed to sink are really sinking?
Why, have all these ships in daily basis actually disappeared? The greatest evidence is that all these ships still exist.
I see no evidence that any of those ships still exist.