English to Italian Other Ships, Sailing, Maritime

I'm translating from english into italian a book about sailing yachts, where I found this sentence.

Cold weather causes any sailor *worth the salt in his or her blood* to put the compass needle – whether literally or figuratively – steadily on South, as the Caribbean exerts its allure.

My proposal of translation, based only on intuition, is:

L’arrivo dei freddi spinge tutti i navigatori *degni di questo nome* a puntare l’ago della bussola – in senso letterale o figurato – dritto verso sud, visto che i Caraibi esercitano la loro attrattiva.

But I didn't find any translation of this idiomatic expression. Is that an idiom typical of the sailing world?
Do you know it?

thank you