Generally Stamford or AtuoBac should sell the covers...
Understand the pain of your car parking at shipyard due to sand/grit blasting & sea breeze which cause ur car to be rough/corroded after few days parking.
But do take note if strong wind blows.. the car cover might fly away & be of no use at all... I saw many of this situations happens at my workplace also...
There's pros & cons using car canvas..
Pro: Protect paintwork from killer weathers & dust particles.
Cons: Straight after you parked & cover ur car, the engine/car heat takes longer time to cool down & also again bad for your paintwork in long term. // You will get wet if it's raining as you need to keep ur canvas... 
BTW i'm working nearby shipyard too.... My car paintwork consider gone case liao....
