whats cosidered deep fishing

[Demon]

I have been trying to catch one of those bone fish for almost an hour but I havent seen any, so how deep do we have to go to catch one? do we have to be far underwater? or can we do it from the surface?

[smurfy]

You have to do it from the surface.
40-50u is deep enough.
They are both Large fish (not colossal).
It took me 20-25 casts before I caught one.

[taniwhat]

Round 60 here, but yeah they did eventually front up.

[PepeMilagro]

I usually fly to a big open water area and aqualand.
Fish while standing on the ship.
And used the bionic bait.

[Shadow Strider]

You can only cast the fishing rod from the surface.

Here's a rough depth guide that tends to serve me well (the edges between these groups is not well defined though)
0-10 small
10-25 medium
25-50 large
50+ colossal

All fish can be found at greater depths, so small fish can still show up at 50+ but at a lower %.

You can use the terrain editor to increase the depth of the water if necessary

[Strauss]

I just tried and its quite easy in the startup system.
I got the fish in the Enbayneu XI planet - Juduppka system (startup system),
You just need to find the spot where water are 50+ depth.
Call you ship on the surface and land on your ship.
Wait for night, usually midnight the easier. Equip with Shadow lure and cast the line.
I usually get every 3-5 try.
PS. I build base for the fishing spot in the startup system.