Because the unit  depends upon the continuing free movement of the blades about their mountings and of the boss about the blade carrier assembly it is essential that these bearings surfaces remain free and well lubricated.

Kiwiprops are not recommended for service where they may be in a mud berth and the boss is covered with mud or a very dirty slurry at low tide.

While there are seals on all the bearing surfaces – this environment is so harsh that we cannot recommend installation in these situations.