By Charles Kennedy of OilPrice.comThe volumes of Iranian oil stored at tankers in and around the Strait of Hormuz have jumped in recent weeks as Iran considers ways to circumvent the U.S. blockade in the Gulf of Oman aimed at choking Iranian oil exports.The number of tankers laden with crude but sitting in the Persian Gulf and near the Strait of Hormuz has jumped since the U.S. initiated in the middle of April a naval blockade to prevent Iranian oil exports and force Tehran into a deal, a Financial Times analysis of shipping and satellite imagery data showed on Tuesday.Data from the U.S.-based non-profit United Against Nuclear Iran (UANI) showed that the number of tankers in the Gulf laden with Iranian crude and petrochemicals has now jumped to 49, up from 29 before the U.S. blockade began on April 13.Separately, UANI and FT have identified more than a dozen tankers clustered near the Iranian port Chabahar outside the Strait of Hormuz but within the line of the U.S. blockade.Ship-tracking and maritime intelligence analyses pointed three weeks ago that Iranian tankers laden with oil were loitering in a cluster near the port of Chabahar. The cluster signals that Iran continues to load oil on Iranian tankers that are trying to leave the Middle East region. On the other hand, the piling up of ships outside the Strait of Hormuz but inside the U.S. blockade line suggests that the American interception of vessels is working.Tanker Tally at Iran’s Kharg Island Hits Post-Blockade Peak: BBG