I strongly doubt there are any non-fiber submarine cables. Fiber's main strength is range; trying to run signals over electrical conductors over hundred-km-plus distances is not cost-effective and hasn't been for decades.
(It's been done historically, but with very heavy cables, very high endpoint power levels, lots of repeaters, and really poor throughput.)
(It's been done historically, but with very heavy cables, very high endpoint power levels, lots of repeaters, and really poor throughput.)