RHD or LHD?
Just tried to crossed Saudi in a RHD and it is not allowed, had to pay many hundreds of dollars to be transited on a truck.
Only Khartoum embassy will issue you the 3 days transit visa, after a fight.
Ferry to Jeddah was fine - $150 for one person, cabin and 4x4. took 6 hours to do all the port bullshit in Suakin. Saudi side very professional, easy if LHD, not worth it if RHD.
Saudi people not easy to deal with at the embassy etc
When I was in Somaliland there were boats going from Berbera to Yemen etc.