The upcoming Protection and Indemnity (P&I) renewal is poised to be the most challenging in a decade as a result of difficult economic conditions for ship operators, poor underwriting results and some of the largest claims in history, according to Willis Global Marine, a division of Willis Group Holdings plc (WSH:NYSE), the global insurance broker, in its annual P&I Market Review. The P&I market results last year (2011/12) showed a 13% increase in incurred claims, a 5.9% underwriting loss and only a 2.7% investment return. Total market free reserves increased marginally (4%) but tonnage increased by 9% over the same period. The market is therefore larger, but proportionately slightly weaker than the previous reporting period.