Baltic Sea Anomaly

In 1937 as WWII continues, a fishing vessel leaves the safety of the harbor, headed out to The Baltic for a month's worth of fishing. The ship's Captain is called up to the bridge to offer his opinion of a strange light in the night sky that his crew have been observing for several minutes. Completely perplexed the Captain can offer no explanation as to what he and his crew are witnessing. As they continue to watch the small light off in the distance approaching at a rapid rate of speed. Suddenly the light is close enough that everyone can see that it's a flying craft, like no other. Speculation circulates amongst the crew that it may be some sort of weapon developed by the Germans. Soon it begins to roll from side to side as if it's losing control until it ends up splashing into the Baltic Sea - disappearing under the surface to one side of the fishing vessel. The sea is disturbed enough that the fishing vessel rolls from side to side. Everyone on the crew is 'lost for words' and the whole experience leaves everyone scratching their heads.
Captain Perez decides to make some detailed notations about the location, and what his crew has just witnessed, but he encourages his crew to ignore the entire incident, and focus on the task of fishing. Later that week, in accordance with the War Commission's suggestions, Captain Perez submits his findings to the local department of commerce and he wipes his hands clean of the entire incident, where it sits for decades before being revealed to members of the OceanX Team who suddenly take an interest in attempting to figure out what actually took place.