How long does it take for growth to build up on an unpainted hull?

[ship happens]

I'm going to be in the same situation as Pescador except my boat is aluminum. Thanks to Lionsgate Marin's new arrangement forcing all boats off the premise by the end of June, I now need to find a moorage and leave the boat off of the trailer and leave it in the water.
I take it that all comments and concerns mentioned above apply to aluminum boats as well?

I spoke with my paint guy and think I mentioned this in an earlier post, however he's doing 6 coats of interprotect and applying micron ontop leaving a 1inch border of interprotect

 

[ziggy]

I moor my boat, a stern drive, for most of the year and have real issues with marine growth. I was recently discussing this with some other boaters in the Marina that had similar boats. They had rigged, for lack of better terms, a curtain that covered the outdrive and essentially the submerged stern of the boat. I was amazed at how much less growth they had. Not sure if the curtain limits sunlight or water circulation. I should note that my lower leg was professionally painted with anti fouling paint, it it seems to do very little. Think I’ll try the curtain idea after I pull her for cleaning.

 

[BC Coast Pilot]

I moor my boat, a stern drive, for most of the year and have real issues with marine growth. I was recently discussing this with some other boaters in the Marina that had similar boats. They had rigged, for lack of better terms, a curtain that covered the outdrive and essentially the submerged stern of the boat. I was amazed at how much less growth they had. Not sure if the curtain limits sunlight or water circulation. I should note that my lower leg was professionally painted with anti fouling paint, it it seems to do very little. Think I’ll try the curtain idea after I pull her for cleaning.

It's sunlight, I moor in a North facing boathouse for the last 3 years. I now have zero growth. The other factor is to reduce the salinity which also reduces growth.