Aluminum swim platform design
 

I am in the process of building an aluminum swim platform for my boat. I am constructing it of 1x3 aluminum tube. I am trying to decide how much gap to leave between the slats. A buddy says 1/2" so that no body gets a toe stuck between them while jumping off. I like the idea but it leaves me no room to weld the sides of the slats. Any one have any opinions on this?

I just measured mine. Its 1 7/8 x 7/8 flat Rolled tube with 1/2 spacing, With plenty of room for mig or tig to get in