Currently all the shipowners are covered by insurance, but for the HNS there is no.... Basically when you have no specific regime, the fallback regime is the one integrated under part 3 of the Marine Liability Act, and your liability is capped depending on your tonnage, and depending on the type of liability.
The limits are much lower than the ones under the HNS convention, and you don't have access to reform. The fallback liability regime is the one under part 3 of the Marine Liability Act, which incorporates another convention on the civil liability of ships. So it's a kind of general provision that applies if you don't have another specific convention applying. When you have crude oil or bunker oil, you have other conventions, other regimes that kick in with higher limits, and there is access to the international fund.
Now with the HNS convention, another specific regime would apply and would set higher limits, which, if my memory serves me right, are $185 million for the shipowner's liability when the spill is from packaged HNS and $160 million when it's from HNS carried in bulk. On top of that, you have access to the international fund that allows the claimant to basically be covered up to $400 million.