I have a valid B1 visa, but the I-94 stamp is expired. Because when I entered the US the immigration employer stamped the I-94 and wrote limited stay for one month. So, I submitted the I-539 Application To Extend my stay and I received a receipt (I-797c form). Can I travel by cruise to the Caribbean islands and then return back to the US? Will I be allowed to enter the US with the receipt?
You can leave, but you cannot return without a valid visa. Automatic revalidation would allow you to return without a valid visa in some circumstances, but, for a B visitor, travel to the Caribbean does not fall within the automatic revalidation program.
In any event, when you leave the US, you abandon your application to change or extend your status, and your subsequent application for entry to the US will be considered as a new entry. Similarly, even after your extension of B status is approved, your departure from the US and application for re-entry would be considered as a new application for entry for which you would need a new visa (unless the trip outside the US qualifies for automatic revalidation).
I forgot about your valid visa. Since you have one, you can in theory leave and reenter the US. But your extension application will in any case be abandoned. So you would have to make the same case on reentry as you had made in your (by that point abandoned) extension application.
You might also have trouble convincing the cruise line to let you board; check with them before booking. An additional risk, and this would be a show stopper for me, is that if you're denied entry, you'll likely be detained, perhaps for a few days or even weeks, and removed. That's because, unlike most people denied entry, you won't be able to turn around and go back where you came from.
If you leave the US, your pending I-539 application will be considered abandoned and will be denied if you don't withdraw it. In this case, it may be better to withdraw the pending application when you leave so you don't have a denial on your record. Once you leave the US, the I-797C serves only to help prove your past compliance and has no ongoing validity.
You can re-enter the US using your valid B1 visa. However, the border officer may question your previous long stay and whether your activity in the US is consistent with a B1 visa. This would be similar for anyone who stays a long time on a B1 or B2 visa and then leaves and tries to re-enter soon afterwards. If the officer decides your activity in the US isn't consistent with your visa, it's possible you could be denied entry.