Fuel Tank Vents

[ca va]

The boat is an ex-Customs chase boat built in GRP - weighs about two tons. It has a small cabin frd. It is now fitted with 2 x 200hp engines. It both floats and does 60 mph!

[milutin]

OK. thank you ca va very much for your answer. then, can someone tell me, can i install 120 gal petrol tank and mercruiser 3.0 stern drive in 20foot boat (overall Length 20' 3" overall Beam 6' 10", like this one on the picture), or it is "too much"

thank you

[Mr Efficiency]

A litre of petrol weighs about 730 grams, so the difference in weight between 500 litres of water and 500 litres of petrol is about 135 kilos, which is a small sumo wrestler !