Memorial Plaque

SPOILER

Credit to Sin_Vraal on IRC for most of this solve.

Use each digit of the dates given to pick the corresponding letter from ship/plane name.

i.e. the first one is 1872 The Mary Celeste. The 1st, 8th, 7th and 2nd letters are TCYH.

The following is the result

TCYH
SRSN
AUY5
SDOD
GITT
UAVY
MLER
SERD
FRRR

At 4:15 in the video, we are given a clue. Green flares launch up one at a time from one of four different positions.

_^__ (2)
_^__ (2)
__^_ (3)
^___ (1)
__^_ (3)
_^__ (2)
_^__ (2)
___^ (4)
___^ (4)

This tells us which letter to pick from each group of four.

This gives CRYSTAL DR.

Dr. Ray Brown found a crystal while scuba diving in the Bahamas.

Answer is Ray Brown