Background
As part of my “lemonade” week, we were with Lora on the Marissa looking at some targets pretty far south of Point Loma and needed a second dive at a reasonable depth. I had dove the Corsair in that area a while ago and thought it would make a good target for a photogrammetry model. It would also allow me to practice building a model with two sections of a wreck separated by sand.
Done!
Tyler and Lauren gave me a 10 minute head-start on the dive to start building the model without anybody else in the water. I got down and the visibility was pretty good. I started working on the engine and then moved to the fuselage, making sure to take enough pictures of shell, rocks, and other things in the sand in hopes of “stitching together” the two sections. I then photographed the starboard side of the fuselage, over the middle, and then the port wing. I went back to the engine on a different “path” as a backup.
I repeated that process a couple times and ended up taking 770 photos and then built the model. It was waaay more photos than I needed. When I used the “Reduce Overlap” function in Metashape, I think it got rid of at least half the photos. Better safe than sorry!
Dive Highlights & Photos
As mentioned, the visibility was pretty good. I wish I had taken some wide angle photos in the beginning before settling in to take all the detailed photos for the model. I’m still building my “standard process” for documenting wrecks.
I hand’t noticed in on the dive, but Tyler mentioned a torpedo ray that was buried in the sand in front of the engine. There was also a cool scorpion fish that was sitting on top of the fuselage and didn’t move the whole time (until the open circuit folks came along)!
One thing that I noticed for the first time is that the port wing seems to be “folded back” on itself. I say “seems to be” because I’m not 100% sure. There is an interesting piece of the airplane on “top” of the wing just at the rear of the fuselage section and it has an interesting semi-circle which I thought was the end of the wing “folded back” but the more I look at it, I get convinced that it is NOT the end of the wing. Maybe somebody else can identify it. I’ve included a schematic / cutaway of the Corsair as reference.
Below are a few photo highlights of the dive. Note that the water always seems to be very “green” in that area and so it is hard to get a good, accurate color balance.
Photogrammetry Model
I’ve included some screen captures of the model along with some notations and a link to the online model at Sketchfab.
Here is a link to the on-line photogrammetry model:
Below is a reference schematic for the Corsair.
