A frame rail assembly for a boat dock structure includes a frame rail member and a removable resilient rub-rail member. The frame rail member includes a first side configured for securing the frame rail member to a side of the boat dock structure; a second side opposing the first side; a first channel extending along a length of the frame rail member; and a second channel below the first channel, the second channel extending along the length of the frame rail member. An interlocking frame rail system for boat dock structures includes a first frame rail member, a second frame rail member, and an upper connector member extending along at least a portion of a length of the first frame rail member and at least a portion of the length of a second frame rail member.