课文详注 Further notes on the text
1．Fishermen and sailors sometimes claim to have seen monsters in the sea. 渔夫和水手们有时声称看见过海里的妖怪。
to have seen是不定式的完成式结构。不定式的完成式用于不定式的动作发生在谓语动作之前的情况：
I'm sorry to have taken up so much of your time.
对不起，占了你这么长时间。
I'm glad to have met your family.
我很高兴见到了你的家里人。
She seemed to have cleaned the room.
她似乎已打扫过房间了。
不定式的完成式常用于believe，declare，find，say，see，know，think，understand等动词后（这些动词常用被动语态）：
She is believed/said/found to have gone to Australia.
人们确认/说/发现她已经去了澳大利亚。
He is thought/believed to have been killed in an air crash.
人们认为他在一次空难中丧生了。
不定式的完成式与表示意图、希望等的动词连用时有独特的含义：
I meant/intended to have invited him, but I forgot to do so.
我本想/本打算邀请他的，可是我忘记了。
I hope/plan to have finished by 12.
我希望/计划到12点钟以前就已完成。（相当于将来完成时）
2．at times，有时，偶尔。
At times I feel that he is not honest.
有时我觉得他不诚实。
He comes to see us at times.
他有时来看我们。
3．…they are rarely caught out at sea.……它们在海上极少能被捕到。
A small fishing boat was carried miles out to sea…
一条小渔船被拖到了几英里以外的海面上……
这两句话中的out分别表示“在外海”、“向外海”：
When her little boat was caught in a storm out at sea, she thought no one could help her now.
当她的小船在外海/远海遇上风暴时，她觉得那时没有人能够救她。
Don't sail out to sea in this weather.
别在这天气出海。
4．this was no ordinary fish, 这根本不是一条普通的鱼。
no的否定意味比not（a/an）要重（用于名词或形容词之前、系动词be之后）：
They are no friends of ours.
他们根本不是我们的朋友。
This is no easy work.
这绝对不是件容易干的活。