RE: Boothbay Oyster boat
Tug Guy, They are under the main deck and are used for putting weights (lead shot for ballast).
I built one last year and I put the main deck on before I had it properly weighed. I had to drill two small holes in the area of the elipical holes in order to add the shot along with glue to keep the shot from moving around.
The holes are hidden because I also put in a diesel sound maker and it is in a box on deck which covers the holes.
Kevin