Multihull or Monohull

[44'cruisingcat]

Originally Posted by Thumbs Up

5. In order for a Cat to perform well it must be built very lightly. The use of modern materials and engineering has solved this but think about this: You are capable of twice the speed or more but the impact resistance of your hulls is probably less than half that of a heavily built mono so if you hit a floating log or something the chance of major damage is a lot more. You won't sink but it will be very expensive.

Agree with most of what you say, but this.

The use of better materials has meant that strength no longer equals weight.

For example - the first boat launched of the design I have was sailed onto the rocks at Great keppel at 6 knots. Sailed right up onto the rocks until the boat stopped.

The damage? Virtually nothing. Apart from damaging the kick up rudders when reversing back OFF the rocks, the boat was undamaged. A tiny dent in a sacrificial keel skin, that's all.

(The rudders were damaged because they are designed to kick up in an impact with the boat going FORWARDS. When the boat was reversed the rudders caught on the rocks and were dragged back down. Understandably, in the panic to get the boat back off the rocks, the crew never though to lock the rudders in the raised position.)

The reason the boat was so lightly damaged was because it was so light. Less weight meant less inertia, lower point loads on impact.

Think about it - if you dropped a soccer ball made of styrofoam off a tall building it would land undamaged. Drop a ball made of 5mm steel, 10mm fibreglass.....

[D&D]

Originally Posted by Thumbs Up

The Ultimate boat is the one that you have. If you want to go cruising you can already be doing it. It doesn't matter what kind of boat you have. It doesn't matter if you don't go around the world. Cruising is more about making do with what you have and self reliance. It is about making it to the next port or anchorage, fixing stuff without the proper resources, provisioning, and waiting for the right weather so you can do it again.

Hear! Hear! Well put, along with a lot of the rest of your novel...

[barnakiel]

If shallows are your main cruising area I would definitely look for a shallow draft or lifting keel thing. Cats are great as are some french monos.

b.

[snort]

Never seen a monohull vs. multihull debate.
Good show!

[dirkdig]

Cats with dagger boards can be good,
But Catanas have been known to have them snap and at $6000 each it can get expensive very quickly.
I know of a few 471 Catanas that have had this happen.

[44'cruisingcat]

Daggerboards should snap if they hit something solid. Prevents damage to the case.

Other than that they should never break. They should be built so there's a sacrificial foam/lightweight glass end on them, which would be quick and easy to repair.

Also in strong conditions, the boards shouldn't be fully down.

[Lagoon4us]

Originally Posted by 44'cruisingcat

Daggerboards should snap if they hit something solid. Prevents damage to the case.

Other than that they should never break. They should be built so there's a sacrificial foam/lightweight glass end on them, which would be quick and easy to repair.

Also in strong conditions, the boards shouldn't be fully down.

LMAO this discussion reminds me thirty odd years ago one of the Nichol brothers got me to repair his broken rudder at the end of an extremely hard Brisbane to Gladstone, i was very used to seeing the lower 10% of a board done in a sacrificial foam glassed over with the rest of the board being laminated cedar or better.

This rudder's shaft was SS tube with a couple of tangs welded on, the complete core of the rudder was 'Corethane' foam ie green refrigeration foam!!!!!

No wonder the early multi's had a dodgy reputation.

Agree with your comment, whatever we have we manage in different ways accordingly. All boards, rudders and foils need a sacrificial bottom section and green foam suits.....

Cheers

[Therapy]

Originally Posted by Thumbs Up

Don't get me wrong Gemini's are really neat boats for what they are but slapping is a huge problem on a lot of these boats and can be more than just a little annoying, in the wrong conditions it could actually tear your boat apart!

Ahem.

[dirkdig]

They don't need to hit anything to snap, just ask owners if you don't think it happens.

[Mr B]

On my Gemini, I kept the windward side centre board down fully, in strong winds,
it stopped the bows from leaping side ways, especially under the full Genoa,

The Gems very light at the front and does tend to flick sideways with out the centre board down, Fully,

It does tend to get blown sideways with strong winds also, 600 mm draught, its no wonder, hahahahaha

[Jerry Woodward]

Another advantage to multis I have found is the ease of deploying/securing the dinghy. Both times I chartered monos in the Leewards the dinghy was secured on the foredeck and the outboard clamped on the sternrail. Hauling/deploying the dinghy and removing/attaching the outboard was a real pain in the ass and downright dangerous. When sailing from island to island in the Leewards, you really don't want to be towing a dinghy with the outboard attached, and we were forbidden from doing it. So this was a daily manuver. Then I chartered a Lagoon 380. Raise and lower the dinghy on the davits.....done. I realize some monos have davits to raise the dinghy, but I havent seen many in the 36-40' range. Other than this, I really enjoyed the monos, but when I buy my boat it will have dinghy davits and an easy way to raise and lower the dinghy...thus, most likely a multi.

[ty.gregory]

Therapy, come on man, where can I get one of dem B.S. Meters?

[Mr B]

This is one of the big differences between Mono Hulls and Multi Hulls,

Park the Multi backwards onto the beach, Lift the rudders to do so,
Water depth is about six inches, at the steps leading down from the transom,

Use the Cats fridge for the booze, Cockpit for the mixers, Salon for the food,
Down the steps and sit on the beach to drink your sundowners,

Mono Hull. has to be at least 100 feet of the beach due to draught, approx 6 feet.
Were not splitting hairs here on a few inches of depth.

Mono has to dingy to shore, To sit on the beach or get a drink from the Cats fridge, Hahahaaha

Life is so sweet on a Multi Tasking, Multi Hull,
And did I mention, swimming off the bows, Take care with that one tho, It needs deep water,

But it is still personal preference what you get, Mono or Multi.

Enjoy your sail, what ever,

[markpierce]

Originally Posted by Mr B

... Park the Multi backwards onto the beach, ...

Some peoples idea of fun:

[Lagoon4us]

Mono or Multi? Ford or Chev? Soccer or Baseball? Country or City living? Cruise or Race?

Just another decision in life and like all decisions there is emotion, balance, history and a myriad of other considerations involved....

What is very strange in this post is the lack of vehemence???? A recent post concerning thoughts on the Con's of owning a multi bought eventual shutdown of the thread.

Nice to see quality sensible answers/comparisons.