Bermuda weather in October will be the equivelent of weather in North Carolina the same time of year. Should be warm enough for beach most days and water will be fine. Seas can range from bathtub to the Perfect Storm. If one could predict, one would not be typing on this message board , one would be at sea 365 days a year. October is still hurricane season. Are you likely to have a problem ?, no.
Book the cruise and enjoy it . You will love Bermuda.
We have sailed to Bermuda many times in October, as our wedding anniversary is October 15. We have had wonderful weather most of the time and the ocean is warmer than in May or June. It is definitely warm enough to swim, but of course weather can not be guaranteed. We had a lot of showers, when we were there the last time a few years ago, but that can also happen at other times.
Go and enjoy, the price is right in October.
Happy Cruising, Ginnie