Moving on a sailboat - bookshelf speakers?

+1 bkeske

The Vandersteen VLR woods/CT. Designed for exactly that purpose. The 60 hi current watts made by the amp you mentioned should be enough to drive them. I have the older version of this speaker at my mountain house and am driving them with an older Sonos amp. The one thing I'll say about any bookshelf that's made to live on a shelf is that the bass will be a little thin. Without a port there's only so much that can be done. If you want full range down to deeper bass you'll likely need a sub. 

Easy! Get Closer Acoustics OGY. They’re front ported. Are built for SET (but any amp will power these speakers). They use single drivers so vertical / horizontal directivity don’t suffer much from placement. 

ROKSAN Caspian integrated amp driving SPENDOR D1’s might stir your drink.

Good luck to you what an adventure ! As a side note the salt air (I presume it’s the ocean or gulf you’ll be on) will really wreak havoc with the electronics in your system. Nevertheless, having a great audio system with you will certain add to the experience. 

You may want to look into car/mobile audio speakers that are specifically designed for a marine environment.  You are going to compromise the sound quality, but they will at least have a fighting chance (and won't be terribly expensive).  Plus, they are installed into the bulkhead which will make them less likely to be stolen when you are out eating dinner.  

My thought is to get the best marine-grade speakers you can, but plan on headphones for "serious" listening.

But I am also assuming you are going to be on something like a 30-foot sailboat.  If you have Jeff Bezos money and are on a mega yacht, then you should have plenty of air-conditioned space for whatever you want.  

https://youtu.be/pY2R7aOeBLU (30 foot sailboat tour)

vs

https://youtu.be/cm40e1ChozE (mega yacht tour)