Upvote:1
It looks like a fishing gaff. They are hooks which fishermen use to secure fish when they are close to the boat to bring them on board. General gaffs look like big pointy hooks. But they are specialized for all kinds of different types of fishing. This could be an antique squid gaff and the blade part would be called a flying gaff used for killing larger fish before the fisherman brings it on board. Maybe a fresh water eal gaff. Here are some pictures of modern flounder gaffs.
Upvote:2
To me your item seems structurally more akin to a boat hook then a fishing gaff. The prongs do not appear barbed, and the individual you referenced used the word 'boat' in his description. The image below showing older items from the Alaskan coast has a couple of items which look quite similar in structure:
Upvote:3
I asked the same question at Yahoo! Japan Chiebukuro (a Japanese Q&A site).
The answerer replied,
これは昔の釣り竿を置く物
土に挿して使う奴にも見えるんだけどThis would be an old holder for a fishing rod, whose spike is impeded into the soil while fishermen are fishing.
Then I asked him if it had been used on the ground, and he replied,
ただ角度が違うから
船端で水平に出して使う竿立てかもしれんねafter considering the longitude of this stuff, this might also be used as a horizontal holder for a fishing rod, it may be placed in front of a ship instead (so that you can place the fishing rod on the U-type prongs.)
After googling in Japanese "fishing rod, Meiji era, holder", nothing such old came up but a today's holder, which has also the U-type prong.
I am sorry that I am unable to present an old picture of the fishing rod holder, but I think mine would be probably correct since,
For paddle or hook, U-type prong won't work properly.
For fishing gaff, the U-type prong also doesn't serve as a gaff because it is not sharp enough.