Supplementary outboard - mad?

[Grehan]

This is a possibly lunatic question that's popped into my head.

My 50HP Nanni engine is perfect for my 11m boat on the inland waterways, but would probably be underpowered for even a short coastal/tidal passage (although my 11m Southerly yacht's 35HP Yanmar was fine).
If I ever thought about a (very short) coastal hop (flat calm conditions) could I attach a 'supplementary' outboard to my swim platform to up my pushing power?

 

[Seajet]

Snags which immediately spring to mind are that the swim ladder is not designed or built to take thrust, and the engine may get swamped ?

Also unless remote controls were fitted ( far too much hassle ) one would have to start the booster engine once clear of harbour, and stop it before entering, which sounds like a safety harness job !

 

[Boathook]

Canal boats cross the Channel so you should be ok in the conditions you suggested though I don't know your boat (speed, shape, etc). Adding an outboard to the bathing platform could be done but as Seajet mentions there are snags.

 

[TQA]

I might do it in your position but for a different reason.

Out at sea with a bit of a chop might stir up detritus in your diesel tank leading to a stoppage.

Having a backup is good.

 

[Grehan]

Not a swim ladder, but a pretty substantial platform. No real access/safety problem getting down to it (other than the obvious).
I have also crossed the Channel, in the past, in a (replica) Dutch barge, accompanied by a narrow boat. I did not wish to be in the narrow boat. Conditions very benign, otherwise we would not have left Ramsgate.

 

[dmayes]

Hull speed

You don't need that much power to achieve hull speed in your boat, the Southerly had HP to spare so your 50 will easily have enough to spare to push you into any sort of headwind or sea at hull speed. You won't go more than hull speed unless you have something like two 200HP engines. The outboard fitted to a lowering bracket is a good idea for an emergency get you home. It only takes a few HP to push a hull at 2 to 3 knots and dependant on the tide, this will get you somewhere in an emergency.

 

[Seajet]

I worked as deckhand / engineer on a 38m hotel Peniche in Burgundy; I met a couple of young Brits who'd taken a Luxemotor across the Channel, I suspect conditions changed a little on them.

They described arcs scraped on the bulkheads by lights, paintings etc showing an arc of 45 degrees either side which they kept as mementos, and openly said it was the most terrifying thing they'd ever done.

I have read 'Narrow Dog To Carcassone' !

 

[Grehan]

Thanks for all the comments. Just idle musing.

 

[Reptile Smile]

I worked as deckhand / engineer on a 38m hotel Peniche in Burgundy; I met a couple of young Brits who'd taken a Luxemotor across the Channel, I suspect conditions changed a little on them.

They described arcs scraped on the bulkheads by lights, paintings etc showing an arc of 45 degrees either side which they kept as mementos, and openly said it was the most terrifying thing they'd ever done.

I have read 'Narrow Dog To Carcassone' !

I would also thoroughly recommend The Unlikely Voyage of Jack de Crow, and the route of the Mirror dinghy down the Thames estuary, around the Kent coast, and across the channel. Absolutely joyously terrifying lunacy...