Not to be a pian, but if I remember correctly the only place where single skinned tankers were allowed to trade was in Korea, until there was an incedent, so yes, all oil tankers now have to be double hulled.

Had a look at the site, and its a small fleet with a couple new ships en-route, the major bonus here is the existing fleet is all a fairly good age, oil tankers have a decent life in 'em, or they should, about 25-30 years or so all going well. The other bonus that I saw is that they seem to have started out as many shipping companies do as a private investment on charter, and as the profits rolled in they grew. Doubt I would want to work for them, but certainly a good place to make your cash grow.

Not in the oil trade myself, know a few folk that are. All in all seems like a solid investment.