Confusion about usage of ordinal numbers


I came across this sentence: 船に乗るのは二回目だ

It was an example sentence in a Japanese children's book for learning Kanji,
so there's not any context. Because of 目 I took it to mean "this is the second
time that I ride a boat."

How could I switch the subject around to say "I'm riding a boat for the second
time."? I would guess: 今、二回目に船に乗っている. Is it correct to use 二回目に as an adverb
"for the second time" or is there any other (more natural/common) way?




"For the second time" = 二回目に / 二度目に  
cf. "For the first time" = 初めて / 最初に  
"For the third time" = 三回目に / 三度目に"

You can use it like this:

>   * **二回目に** 京都へ行ったとき、金閣寺を見ました。  
>  I saw Kinkaku-ji Temple when I went to Kyoto _for the second time_.
>   * **二回目に** 会ったときに電話番号を教えてもらいました。  
>  (Someone) gave me his number when I met him _for the second time_.
>

So your sentence "I'm riding a boat for the second time" can literally
translate to:

> 二回目に船に乗ります。← You'd usually say this before riding the boat  
>  二回目に船に乗っています。← You'd say this while you're on the boat

These are grammatically correct and natural, but we'd usually say it more like
船に乗るのは（これが/これで/今回が/今回で）二回目です。or 二度目です。




"For the second time" = 二回目に / 二度目に  
cf. "For the first time" = 初めて / 最初に  
"For the third time" = 三回目に / 三度目に"

You can use it like this:

>   * **二回目に** 京都へ行ったとき、金閣寺を見ました。  
>  I saw Kinkaku-ji Temple when I went to Kyoto _for the second time_.
>   * **二回目に** 会ったときに電話番号を教えてもらいました。  
>  (Someone) gave me his number when I met him _for the second time_.
>

So your sentence "I'm riding a boat for the second time" can literally
translate to:

> 二回目に船に乗ります。← You'd usually say this before riding the boat  
>  二回目に船に乗っています。← You'd say this while you're on the boat

These are grammatically correct and natural, but we'd usually say it more like
船に乗るのは（これが/これで/今回が/今回で）二回目です。or 二度目です。

