Hawaii’s largest ocean shipper said “rapidly rising fuel-related costs” are prompting it to raise its fuel by 3.5 percentage points to 27.5 percent for its Hawaii- mainland service. In addition, the state’s largest ocean shipper is boosting its fuel surcharge by 3.5 percentage points to 29 percent for its Guam/Commonwealth of the Northern Mariana Islands and Micronesia service. Matson said that if fuel prices don’t decline soon, it will need to make further upward adjustments. Horizon Lines, the state’s second-largest ocean shipper, typically matches Matson but could not be reached for comment. Horizon’s surcharge is at 24 percent for its mainland-Hawaii service.