Being in the rv side of off the grid and self contained setups, lithiums are widely used and comes with a wider range of quality and results. This gets discussed all the time. The issue when buying lithium batteries is that local battery outlets are pretty selective in wanting to sell them. Purchasing from Amazon comes with a risk, mainly service and quality. The huge selling point is that "you can get ten years of service from them" I say if there was any ifs, ans and butts to that story, then you can attach that to lithium batteries, dependent on their owners a larger percentage of the time.
Battle Born batteries offers a bit better quality and service. Of course that comes at a higher price than the constant quality issues, but much cheaper with the Chinese built lithium batteries that pops up overnight on the web for sale. The quality is all over the place. Of course on the opposite side of the conversation pertains to the owner. Proper charging does require a dedicated battery charger. Of course a regular charger will bring them up to snuff enough to use them.
But for the sake of this topic here dealing with electric dinghy propulsion, there is some advantages over the gas powered small outboards due to the simplicity , as long as you have the ability to charge them. Charging with solar can do the job when you are in remote areas. But thats not instant like gas powered outboards if you run it on empty.
Lille , great shot, enjoy your trip in the Windward Islands, wish we were there . Everything electronic continues to evolve at a break neck speed. When using lithiums, keep in mind that cold temps can restrict recharging too on some brands. The earlier versions came with a feature to warm them. On the opposite side you can install them inside, sideways without the same problem as lead acid batteries.