It would be very difficult indeed for an SSBN to traverse the Suez Canal without somebody taking pictures.
It isn’t deep or wide, and the US pays a fee to Egypt for using the canal. Just like we do to every canal used by any shipping.
And there may be a Russian or Chinese spy watching the canal … but I bet that they just subscribe to the various shipping guides now available on the Internet.
So the question is why they used that route, where it came from and where it is going next.
“It would be very difficult indeed for an SSBN to traverse the Suez Canal without somebody taking pictures.”
Same for converted SSGN’s.