F*ckin lol.
If its enamel, you need to call a specialist, who are usually expensive.
If its plastic you can fix it piece of piss if you have:
a die grinder,
some spirit type cleaner preferably acetone,
some white gelcoat + catalyst,
a pencil shaped piece of plastic or wood to blob the gel into the outermost cracks,
a wooden block 4" x 2" x 1",
180p sandpaper,
1200p wet and dry paper,
a bottle of 3M fast cut cutting compound,
some mutton cloth or any rag.
Thats one way to do it, should be plenty strong enough but if you're worried about it breaking there are other ways.
if not it will either be awkward to do or it will grate at your ass whenever you bathe