The fiberglass tube for the bow thruster was installed. Under the V-berth, tie lines were dropped and pilot holes were drilled on the port and starboard side of the hull.
Using a string and two points on the keel, I confirmed the pilot holes were centered, then a jig was passed through the two pilot holes. The jig comprised of a steel rod that was sharpened to a point on one end and bent twice such that the point was a distance from the axis of the rod that was the radius of the fiberglass tube. Note the two red chalk marks that were used to confirm the pilot holes were centered (made by tying a piece of chalk to the end of a string that was taped to the leading edge of the hull). The jig was then used to scribe the hull.
A saber saw with a diamond blade was used to cut out the oval that was scribed.
Note the hull is 1-1/4″ thick where the holes were cut.
The tube fit the holes that were cut perfectly.
Before glassing the tube in, the hull was ground down past the gel coat.
Once glassed in, the excess tube was cut off, leaving enough of the tube protruding to create the leading hydrodynamic edge.
After glassing in the outside of the tube, the leading edge was flared to improve hydrodynamics. Cabosil (collodial silica), a very hard material, was used to flare the leading edge.
Low density (fairing) filler was used to smooth the installation.
Finally, the inside was fiberglassed.
The entire project took two weeks.