I wouldn't go with that FWIW. Looks like a lightweight play bike, not good for transporting goods, no passenger possible. Gimmicks are great, but for a tender to a boat, I'd go reliable, well known and predicatable. Especially if travelling out of the country. Few things appeal to me less than the idea of arguing why a border guard should understand that my piece of paper makes a not originally road legal bike road legal in a language I don't speak well.
CT110 or Yamaha 125 would be my choice. or a light small 250 if you can afford the space/weight. Something with an actual dealer network, common parts and known reliably. If you really want to go lighter still, a 50CC 2 stroke scooter upgraded to 70CC scooter would work well as well. That FX strikes me as the worst of both worlds; The motorcycle equivalent to a jetski. I once upon a time considered a similar bike as a cool alternative, I thought, a GASGAS with a hotted up WR250F engine in it.
I am very grateful I didn't. Expensive and frequent servicing, constant demand for parts and hard to find. As a on boat motorbike I'd think toughness and reliability would be priorities.
I have a WR250R insetad, which shares little in common enginewise, tough, reasonably light, 42, 000 km valve service intervals(vs 300, not a typo, for the GasGas).
Something that is commonly known and predictable and tough would be better in my books.
EDIT: This is a rider I met along the road, I think he's in Albania in the picture. If he can ride this all over the world, you can use it as a tender reliably I think. Fuel injected, reliable, used as delivery bikes worldwide.
EDIT2; BL, I wouldn't want one of those on my boat! Can't take it on the road around here, and could get you in a lot of hot water just about anywhere.
$5 a day, dirt roads RTW on a 125cc Yamaha YBR - ADVrider