Retevis H-777S Long Range Walkie Talkies for Adults - 10 Pack Two Way Radios with Earpiece & Mic, USB Rechargeable, FRS Handheld Radios for School Security, Church Events, Construction Sites and Outdoor Adventures

We bought 20 of these for a family cruise of about 20 people on one of the Oasis class ships, the largest cruise ships in the world. We were THRILLED. I mean, this saved the vacation. These ships carry 5,400 passengers and 2,100 crew; so, we found we almost never noticed the same people twice, and gathering those in our group would have been impossible except for scheduled dinner time.Other folks who noticed the walkie-talkies and the clear communication would frequently tell us they wished they had done the same.We tested on-land range at 1 mile with many obstructions (houses and trees), and we could still communicate. The interference at this range was starting to get uncomfortable, though.On ship, we could easily communicate with folks in Port and within miles to unobstructed land (like the beaches near the cruise ship with line-of-site).Range on ship is dramatically reduced by all the steel. Here are our results:Deck 9 aft to Deck 16 mid: Perfectly clear (almost had line-of sight given we had an interior balcony that could see deck 16)Deck 16 midship to Promenade Deck 5: Some interferenceDeck 3 midship to Deck 9: Not possible (if there was possible line-of-site, like with balconies, it would likely work)Forward to aft of ship: Only worked when on the top decksThe battery life is fantastic; most people only had to recharge once on our 7-day cruise. I bought a 3-port USB adapter so I could charge my phone and both talkies for our room (the talkies come with two single USB-to-AC adapters which can become problematic on most other cruise ships which have very limited power outlets), but ended up not really needing to worry about charging much.Channel selection comes with a convenient, audible announcement of the new channel - very helpful.We were almost always able to communicate, and these walkie talkies significantly optimized the time we could spend together (instead of looking for each other!).