Too much geometric straight line and square grid precision.
If you found a terrain feature that was preciseley straight for 10 miles you would no doubt find that extraordinary, and begin to question it's 'natural' origin.
How much more so when this is the case for 1774 or 3504 nautical miles? These are staggering distances by any standards! A line
along the ocean floor that is absolutely straight, containing a consistent ribbing structure between two parallel edges several miles apart, for the entire distance over thousands of nautical miles is extraordinary, to say the least.
To find that these straight lines create distinct patterns and are associated with 'interesting' adjacent structures, including a consistently
sized high precision square grid pattern (0.66 x 0.66nm squares) adds fuel to the speculation. What are we really looking at?