GPS interference was reported in the vicinity of Port Said, Egypt on April 6th, according to US Dept of Transportation marine department MARAD.
The interference is resulting in jammed, lost or otherwise altered GPS signals affecting bridge navigation and other communication equipment. MARAD advised vessels to exercise caution when transiting this area.
https://www.navcen.uscg.gov/?pageName=gpsUserInput.
https://www.marad.dot.gov/msci/alert/2018/2018-004b-gps-interference-port-said-egypt/