You are bragging about not changing your impeller in 25 years?
I wouldn't leave the dock with you on that boat if it was sailing after Noah's arc had sailed and it was my only hope!
I am not bragging about anything and i wouldn't let you on my boat as i could not stand the constant critique (and expense) of trying to keep you happy. After all, nothing must be older than 10 years as it might fail, even the whole boat.
The impeller pumps and pumps strongly.
When it doesn't I will change it... there are two impeller spares on board, and a spare pump, and two starters, and a spare gearbox, and a spare alternator.
As for seaworthyness and the Arc and all that, well my boat took me across the North Atlantic, you know (?) through the usual gales and so on, and it still floats, and i changed the coolant impeller 25 years ago.
How far has yours sailed without stopping for spare parts? Six times round the world no-doubt?