In reply to malky_c:
> To be honest I doubt a lightweight plastic trowel is going to get a great deal deeper than my heel.
You'd be (pleasantly) surprised - I've had the equivalent coghlans version for 15 odd years and it is much better than the alternatives, i.e. boots, stones or sticks, and it's quicker.
Or it could be that as an archaeologist, I find digging a hole with a trowel second nature...