An increasing number of these projects use new construction, rather than conversion from the diminishing supply of existing tanker tonnage of suitable size, configuration and quality, for long-term development of major fields. As of the fall of 2002, 23 FPSOs (11 newbuild and 12 conversions) and 5 FSOs (3 newbuild and 2 conversions) were under construction. Notwithstanding the new construction, the ability to maintain these assets on site and in full production over the long term is very important. Where a typical shuttle tanker may have a day rate of $20,000 to $25,000/day and a deep water Mobile Offshore Drilling Unit (MODU) may earn $150,000 to $200,000/day, one day of lost production on an FPSO can easily be valued at $2,000,000.