@naivere ,
I think what he's saying is, "It's a shame I can't run back to dry land" / "because this bridge (pier, probably) is too narrow." Unsure if this is MTL. If so, there might be confusion about "I can't get close to it" as in, "with that spear's reach, I can't get within sword range."
This is all a guess because the LN/WN (
Trash skill Gacha – Chapter 12) has him being attacked on a beach.
Disclaimer: I don't know the manga, can't read Japanese, etc. I'm extremely grateful to all scanlators, and am not criticizing. Any scanlation is better than no scanlation. If it's inconvenient to edit this, NBD; just trying to say "thank you" in a helpful(?) way.