Answer
A – Periodic survey of class is done to ensure to maintain/verify the condition of vessel and done thru: A, I, S, Continuous survey system.
Why to do intermediate when annual is being done?
Scope of intermediate is bigger than annual. During intermediate the surveyor would include checking of hull structures,machinery, boilers, Pr. Vessels., eqmt., elec eqpmt to ensure they remain in good condition. Whereas annual scope is general condition of vessel and check on particular machinery.
In case of Intermediate survey carried out during 2nd or 3rd annual survey and should not replace the annual survey.