There are a lot of factors which are not addressed.
resistant is the material?
There is no anti-foulant paint
that works well that is compatible with aluminum
other than TBT...which is now banned in most developed countries.
Most of a cargo ships weight is in its cargo. The article says it can cut a ships weight by 30%. Lets say for example, if half of a ships weight is cargo, then the real number is a reduction of 15%. Is a 15% reduction in displacement
If this deforms on impact, then how do tugs come alongside a ship? How does it hold up to impacts from hitting debris underway? How well does it hold up to being pressed against a pier?
How flexible is this material? Ships, just like bridges and aircraft, must be able to flex in order not to crack.
How expensive is this material to create and to work
Is it repairable?