Loch Ness: Who saw it first?

When was the Scottish Loch Ness monster for the first time?

Nessie was first mentioned in the work Vita Columba, Columba’s life, written by the abbot Adomnán on the Scottish island of Iona in about 700th
The Irish saint, St. Columba went to Scotland 563 years to spread the word of God among the heathen natives. He founded the church at Iona and went from there into the Scottish highlands.
On one of his trips he met, according Adomnán, some people who were about to bury a corpse. The dead man had fallen victim to the monster that lived in the vast and deep Loch Ness. Resolutely commanded the saint a man in his company to swim across to the beach on the other side. When the monster turned out did Columba sign of the cross and commanded the animal to not get closer. The beast stopped abruptly and disappeared into the depths.
Loch Ness monster disappeared for 1000 years
After that kept the monster in Loch Ness gone for over a thousand years, up to 1933. When told George Spicer and his wife that they had seen a long, serpent-like creature at the lake’s shore. Others soon came to similar testimony, and in 1934 published a photograph of Nessie.