Nope flight crew is dead. Make a decision if you are capable.
The flight crew is dead? Well, that's new information which wasn't included in the original scenario.
Other considerations which would likely be known to any surviving passenger:
How far is the crash site from dry land? Can an imminent rescue be expected? Or is it something that might take hours, days - or even not at all?
I'm also wondering about the circumstances of the crash. When I've heard of planes crashing into the ocean, usually everyone aboard is lost.
They say that you can use your seat cushion as a floatation device, but assuming that the aircraft doesn't break apart on impact, how much time does one actually have from the time of impact in order to evacuate the aircraft before it sinks to the bottom of the ocean?
Depending on if/how many passengers survive the impact, there would be injuries and people panicking to get out of that doomed flying tube (and as usual, there would be those slowing up the process by taking their own sweet time getting their carry-on luggage).
At least before the flight crew died and while they were descending to almost certain death, they likely would have advised all the passenger to don their life vests, as shown here:
So, they would have had life vests and seat cushion floatation devices, in addition to rubber rafts (as you outlined in your OP). Another consideration might be the temperature of the water and the danger of hypothermia.
As for what choice I would make? I would not choose a flight which goes over the ocean. When I fly, it will only be over dry land. That way, if we crash, we all die together.