No Ron, it was the moon reflecting off a tombstone, not an attempt by a spirit to communicate with you; neither do i believe that the person I spoke to aboard the ship was trying to communicate with me.
I worked on that ship several times over six years during which tme I saw many strange things, but never described anything else as a ghost.

What I saw was solid, human form, with discernible features and left physical evidence of it's passing on the deck; but evidence which disappeared within seconds. I was one of several different people who had encountered the same person/spirit in the same locations over a period of twenty years. Very few people spoke of their experiences until the welders in the dry dock incident. The bosun I spoke too had seen it himself twice, and was present when his brother had died aboard ship. He complained of feeling ill and was told to go and lie down. Ten minutes later the bosun went to see him and found his brother dead from an apparent heart attack; still dressed exactly as I saw him in wet (heavy rain)old fashioned black oilskins and Sou'wester. This guy had been buried at sea in the exact location I encountered his spirit; and at the same time of day he had died. I had no prior knowledge of this event, and had never been exposed to stories about a ghost aboard the ship.

Coincidence? hallucination? natural? Someone playing a trick? No sir it was none of the above, I investigated any possible trace of water inside and outside the accommodation, wooden decks would have shown it, no-one could have manually dried the source that quickly.

I once saw lights at sea that looked like a ships light crossing ahead of me. As we continued on course, it then appeared to be rising and that the ship was not a ship but a helicopter turning towards me at about 500 to 1000 feet. Red sidelight and white light visible, target on radar at same azimuth, clear sky calm sea, no other lights. Turned out to be the planet Venus with a tiny cumulus cloud (the only cloud in the sky) reflecting the red from the rising sun still below the horizon; the radar target was a fishing buoy with a radar reflector on it. But combined it had fooled three very experienced seafarers into thinking it was man made for over an hour.

Yours, Aye. Dave