water + mains cable = bang?

my w/c pump arrived today (eheim 1250), was second hand costing me £62 including a nb waterblock.. anyway im hoping to run this submerged as it would take away the viabrations etc.. (the pump is designed for either sub or inline)

problem = mains cable outer insulation is split a TINY bit less than 2cm from where it enters the pump, there is no way im gonna put this in the water atm! (its still safe outside water imo, but i doubt the inside insulation is as waterproof as it needs to be). i would rewire it, but afaik pump cant be opened, the bit where cable enters pump is sealed and i only have 1cm so theres nothing much i can do in terms of rewireing.

any suggestions? glue/tape of somekind? needs to be 100% waterproof

a lot of silicone?

Remove plug + heatshrink over the split, then replace plug? Or use that self amalgamating tape stuff.

would heatshrinik work? waterproof enuf? im going to try find some spare sillicone if i have some, or maybe buy some, is it expensive?

also any oen used this pump, is it niosy / will i want it submerged in a silent system?

Try a chandlers there are such things as through bulkhead fittings with glands on either end. I dont know if they do them but try Pumpkin Marine, I think they have a web site but I dont know the url

I have a 1250, and it's not particularly noisy to be honest. You can hear it hum, but it'll be a lot quieter than your radiator fan. Plus - submerged, some of the noise will be dissipated (cannae think of the word). Remember to screw it down properly, and make use of rubber grommets if you can to eliminate vibrations.