The best outdoor combination padlock for securing boat storage is the Shield MC40. This marine grade padlock can be used on narrowboats or sea going vessels. With a shackle of 34mm inner height and a diameter of 6.5mm it would fit many storage boxes, making it ideal for securing everyday items, especially when away from the boat. A combination padlock is great when you want to avoid losing padlock keys into the surrounding water.

The Shield MC40 maybe the smallest weatherproof combination padlock we stock but it stands up well against the other major combination padlocks on the market. It is nice and simple to use yet offers exceptional weather resistance even in exposed environments. Ideal for use in those less sheltered spots on the canals where you want that bit of extra security for your belongings or to simply secure items when out at sea.

As you can see it is not a small travel type combination padlock but a high quality sturdy piece of kit. Purely due to the size of this lock, we would consider this a low security option but it is ideal for boat lockers and external storage boxes.

The stainless steel shackle and mechanisms, along with a chrome plated body, means this padlock performs well in the both inland waterway and marine environments. Although we know people using the inland waterways will not have to endure the same harsh environment of those sailing the high seas, it is important to use a high quality padlock.

Therefore it is good to know that this padlock performed well in our marine quality tests, which also included being continually sprayed by very salty water to simulate marine conditions. In addition to our testing, a well known sailing magazine completed their own review of all the major marine padlocks, with the Shield MC40 coming out as Best in Test. If it can stand this type of testing then you can be confident it can tackle both the watery environment of our inland waterway system and time spent out at sea.