Had some gates fitted late last year and the contractor hit the cable which
feeds my outside plug socket and garden lights. Whoever installed the garden
lights connected a normal PVC twin core and earth to the junction box which
feeds the detached garage (by SWA), routed it under my path, then up onto my
fence. The cable is housed in tubular plastic conduit (about 1" diameter)
whilst on the fence and goes to a mini RCD, which then feeds the plug and
lights.

Basically, I want to replace this 'broken' cable between the exterior JB and
the fence.

My questions a-

1) Was going to use SWA but have seen mention of Hi-Tuf.. Can this be
buried? Need to bury the cable under my path for about 3 feet.

2) I don't want to replace the entire cable length to the outdoor RCD, but
want to join the cable on the fence with a weatherproof JB. How do I get a
watertight connection between the plastic conduit on the fence and the new
JB which I will be adding to join the new / old cable?

Thanks