My Dad had a brilliant one years ago, handle was made out of bamboo (like and old cane surf rod chopped down).
There’s plenty of bamboo growing here and there if you can’t find an old surf rod in your Dad’s shed.
Best attribute with Bamboo, was that when wet it didn’t get any heavier so maintained accuracy throughout the whole exercise.
When you get really good at your spearing, use a single prong as it doesn’t rip your flatty apart when you remove it and if the fish is not quite size, it can be returned with less harm.
Hope you don’t drop the spear through the toe of those nice waders you got….