switch mechanism

[Lance0070]

i want to put a unlock mechanism on an rc boat to take my fishing line out to sea and at the push of a button it releases the line, what sort of switch and components would I need, keeping it simple

 

[Bluejets]

$50.00 4 channel rc transmitter and receiver.
$7.00 servo with a pin connected to the servo arm one end and through a support bracket the other.
When ready to release the line, operate the servo, pin pulls out of support bracket and releases the line, simple.

If you want to go with a commercial product, Hobbyking glider tow release mechanism.

 

[Lance0070]

Want something that good for distance of like 100 to 150 meters

 

[Bluejets]

Rc will be good for 500 metres at sea level at least, maybe more.
Depends how high the waves are...

 

[dave9]

Encapsulate the boat so it looks like a torpedo, which you may need to do anyway for seaworthiness, then no need to disconnect the line, reel the boat in with the fish and you also save battery power not motoring it back to shore (and minimize losing it by keeping the line attached, since the sea currents could end up far stronger than a model R/C boat motor can overcome).