Ten tankers carrying various oil products are sitting anchored across the Caribbean awaiting payment for the delivery from Venezuela’s PDVSA, unnamed sources told S&P Platts. The vessels hold more than 3 million barrels of oil products, including heavy virgin naphtha and gasoline blendstock. The troubled Venezuelan company has been slow to make payments for oil product cargoes, but it is making them, one of the sources said, adding that "We did not see them as big buyers for May deliveries of gasoline and diesel, so I guess they feel…