Why not build lined (metal) fuel tanks?

[tanker4lyfe]

Am just wondering. Or is there a design reasoning behind the current tanks that swell?

[Bass Cat Boats]

The configuration of plastic molding vs. cost of aluminum in the odd shapes for maximizing fuel capacities. We have aluminum in Yar-Craft and it is efficient in design and simple. Bass Cat complex configurations are not easy in aluminum and costs would be huge, as they try to leave the sump open when they can for access.

If they just spanned across the bilge as many do it would be simple for us, and savings to us as the manufacturer would be passed to the consumer down the road as cost increases. The cost of servicing bilges, aeration pumps and plumbing would be excessive in our feelings for the consumer.

We do everything for a reason and even aluminum fuel tanks have some swelling under the pressure systems.