Here’s a handy plastic bag dispenser that will fit a lot of needs on the boat or elsewhere.  Davis Instruments is selling a Knot-a-Bag, a small dispenser that holds 32.5 feet of tightly wound polyethylene film that lets you create virtually any sized bag for the task at hand.  Just pull material from the center of the dispenser, cut it to the desired length with the built-in safety cutter, and tie a knot in the end. The Knot-a-Bag material unfolds to 8 inches in diameter, and is made of  recyclable Type 2 plastic.  It's ideal for holding everything from wet swimsuits to doggie doo and is even safe for food storage.  The 0.36 mil. thick blend of high- and low-density polyethylene is strong and creates waterproof bags  when tied at both ends.

The Knot-a-Bag dispenser is only 4 inches high and comes with a clip so you can attach it to a belt, backpack or dog leash. Knot-A-Bag cost $7.99 for the initial kit with dispenser and one roll, and a refill pack with three 32.5' polyethylene rolls is also $7.99.