Hi never tried to post a photo on here. Can anyone tell me what this is please. We went to our boat this weekend and found this substance on the floor and wood panelling. It feels brittle to the touch and has the texture of damp salt. But, it doesn't crumble when scraped off. Also it has no smell or anything like that. http://s1254.photobucket.com/user/maatkinson/media/imagejpg1_zpsae7127b4.jpg.html
It's efflorescence. It's a salty substance left behind as water evaporates.It's most commonly found on brickwork but can be found on timber aswell. You must have damp around that area.