Baydelta Maritime of San Francisco has exercised its option for a second 100-ft., 6800-hp harbor tug from Nichols Brothers Boat Builders. Meanwhile, an order for a similar tug has been received from Minette Bay Shipdocking, Ltd., of Prince Rupert, British Columbia, the company said. The first tug is expected to be delivered in June, with the second Bay- delta tug due in October. Delivery date for the Minette Bay tug is forecasted for December. According to a Baydelta spokesman, the company’s two tugs will be named the Delta Billie and the Delta Cathryn. The tugs were designed by Jensen Marine Consultants, Inc., of Seattle with ship handling as their primary purpose, although they will also be fitted for long-haul towing.