Leak from shower into hall below

Threads with similar problems seem to deal with free-standing showers/trays. My shower is in the bath.
This morning, for the first time, I noticed several drops of water on the hall floor, directly underneath the bathroom at the shower end. I then noticed some paintwork on the hall ceiling to suggest this may not have been the first time (D'OH! - I bought the house 2 months ago, house is about 6 years old). The ceiling was dry when I touched it though but it can't be coming from anywhere else. This wasn't picked up in the engineer's report either.
Anyway, the shape of the bath doesn't help - there's a dip behind it which catches water in a kind of channel. Where the shower screen joins the wall at the lower end, there's a small patch of black gunge.
Am I looking at a big job? Would the house insurance pay for it? If anyone can recommend a plumber in the Kinsale/Cork area, I'd be very grateful. And ideas of what I'm likely to pay to sort it out are welcome too.
Sorry for the long post.
HMC

This sounds like a job for some sealer - clear silicone gunned in should solve this. There may be a break in the joint between your bath and the tiling. Should be easy enough to fix.

This happened in my own house - the tile at the bottom where it meets the shower tray was not sealed.

A handy enough DIY job if your up to it, otherwise any half decent tradesman should be able to tackle and sort this out.