It's really hard to tell from that far away picture and without a picture of the top of the pulpit but it seems that the anchor is not compatible with the pulpit roller insert. A different type anchor( danforth e.g.) without a tapered shaft probably would work better since it wouldn't get wedged in the slot. I suppose some sort of stop bolted to or welded to the shaft that would stop the upward motion before the shaft gets wedged might help but at the same time it might cause the anchor to slap around in seas when stowed.