this generator will be used on a boat to heat a 240vlt water heater which needs a 10 amp system to power it.
First, I'm assuming this is a portable generator, and I must caution that there is a high danger from the exhaust fumes. CO poisoning from generators on boats are a major hazard, not to be taken lightly. Do not put it on the back deck! Or, up on the fly bridge, etc. for that matter. Also have a operating CO detector. (Even if you don't have a generator it's a must have!) At Anchor I would use one on the swim platform occasionally. In my experience a lot of hot water heaters on boats can be used on 120V. and have a 10 Amp breaker. So, I'd inspect the water heater carefully, and it might well be that you can run the Water heater. However, You are at the very limit for that size Gen. set. The actual heating element on my hot water tank is 1500W. 120V AC. Just out of curiosity, why? I had a Marine water heater with a Marine engine water heat exchanger. When the engines where running, coolant was circulated through the hot water tank. So if I needed to shower, the water was often hot, or I could just start the engine and let it idle for a few min.
That small of a Genset are U use is 220V most are 120V. 10amps is normal for a water heater need a larger unit.
seeing as 240V x 10A is 2400W, then no In practice it might, just, or else the breaker would keep tripping off Why do you want to run an electric heater off a geneator ? It's probably more efficient to use a kerosene-burning boiler.