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The UWL 100 is negative and will make your housing front heavy. QUOTE]
Actually it will probably weight the housing just right. My own Ikelite housing (pc1000) feels unbalanced without the WA lens attached.
To get the bouyancy and balance just right on my Ikelite I ditched the twirly knobs that sit on the handles (these knobs it seems, were perfectly designed to snag on hoses and d rings etc.) and took out the bolts on the top. I left the bolts in on the bottom of the handles and secured them with two M8 aluminium nuts. I leave off the lead weighted 'foot' The housing and camera are now just a few ounces negative and the balance is great, I can flip the housing with a flick of the fingers and it does a neat somersault in the water. This means that it's centre of bouyancy is very close to it's centre of gravity -just right.
By the way,the holes left at the top of the handles are ideal for zip tieing on a couple of climbers clips. When I do shore entries I clip the housing onto my bc's D rings and it sits nicely on my chest.( I rest my arm on top of the housing in rough surf when entering -this stops the housing hitting me in the face) Sometimes when on a busy boat I find it easier to clip up the housing and enter the water down the ladder, putting on my fins in the water, -rather than wait to have the camera handed to me.
Phil TK