Anyone Using a High Performance Cat / Tunnel Hull Dinghy ?

[deckofficer]

Am I the only one considering one of the high performance cat/tunnel hulled dinghy? These are made for high speed rescue but also would make a great, economical tender. Some models will accept 50 hp and hit 70 mph, but if you want a planing dinghy with minimum hp, they would be a good choice.

Tunnel hull cat inflatable boat

XTM xtreme tunnel hull cat inflatable

DUX® HammerHead PD-400

High- Performance Inflatable Boats

Tunnel Hull Catamaran Inflatable Boats

[Katiusha]

We looked at them in detail when we were replacing our dinghy (my other half has a bigger-faster-better dinghy fever). We talked to some people who had it. We decided it was not for us for the following reasons:

1. Wet ride - for us a dinghy is a tender, carrying people, groceries, spare parts, and in spare time used for exploration. All cat dinghy models we looked at (even the ones that claimed a dry ride), still ended up wet when there were waves present. Maybe we didn't look at the right ones.

2. Material was not good enough to last a few seasons in the sun - PVC was just a regular grade, not long lasting, and all of them [the ones we looked at] were darker colours - bad for keeping them in the sun.

3. They were made in China - yes, China does produce good quality things, but just before we started looking, we had had to return two (2!!) dinghies of different makes because of poor quality seams. So no Chinese dinghies for us.

4. Slamming into the waves - people who owned them said that they bounce quite a lot and quite uncomfortably (more so for people in the front).

We decided that for us cat dinghies would be a nice toy to use on lakes for fishing and fun, but not for long-term cruising. We ended up with a French 3.10 Zodiac Cadet with 20 hp motor. It's fast enough, and we can fold it on deck for passages.

We also did a study of dinghies in St Martin Simpson Bay Lagoon by dinghying around and looking at other dinghies in use There were at least ... umm... 1000 (?) in season from cheapest to ultra-fancy mega-yacht tenders. We decided that for us the best ones were the ones that provide the smoothest and driest ride, are fast, do tight turns well, are roomy, and are light. Oh, and they have to be fixed easily. So for the next boat we'll be getting Walker Bay. Cat dinghies performance (stability, turns, dryness), by what we saw, did not stand up to better make hard-bottom dinghies.

Disclaimer: we talked to people who owned DUX (2) and Tunnel (3).

P.S. Forgot to add one more thing: after beaching our dinghy through some nasty swell, we decided that one more thing is important in a dinghy: how stable it is through breaking waves. And for us it's a dinghy with a v-keel and good tracking ability.

[ozskipper]

as long as your boat is big enough to handle the extra windage and the added weight of a large OB hanging over the back, why not?

[cat man do]

One built from duflex offcuts

http://www.mahnamahna.com.au/February%202007.html

One from Schionning Design

[Sunspot Baby]

I have an AMI tunnel hull. I am on my third! The first two had transom pull free of tubes. The company has been easy to deal with giving me the first warranty replacement free and then after another two years prorating the second replacement.

So there is the problem. The build quality is just not there. They seem like great folks but when this one dies, I am going back to a good RIB.

George

[deckofficer]

George and everyone, thanks for the feedback. George, other than the obvious lack of quality, how have you liked the AMI ? Does it do what you need well enough, if the 3rd one lasts 10 years you would stay with it? Or does it have all the faults mentioned by Katiusha?

[Sunspot Baby]

The wet ride mentioned earlier is sometimes a problem, especially when you are crossing the harbor in a chop.

I have had both 10 & 11' models and the 11 is definately less wet. The boat is fast in fairly smooth conditions, faster than previous RIB with same motor.

I doubt seriously that this boat will last 10 years. The guarantee (like most PVC boats) is 5 years. I have had other PVC dinghies over the years and I would swear this material is thinner. I received this boat in November and put it in the water this summer. My 16 yr old granddaughter was driving it and bumped our boat going a little faster than normal coming back to the big boat. Didn't seem like much but I developed a leak in the area of contact and have already had to repair the dinghy. Not sure if it was the bump or a previous flaw but as I say, it didn't seem to be a big bump. I have used the previous boats as a make shift tug, pushing and pulling to get grounded cruisers back afloat. Never a problem before.

The concept is neat. Boat handles great but my guess is that if they built this design our of Hypalon, it would be so expensive, no one would buy it.

I really want to like this boat. Great design and nice people, but IMO, they don't have good build quality.

George

[deckofficer]

Thank you George for taking the time to post your experiences. My last tender was Hypalon and never had any problems with it. Even explored the glaciers outside of Valdez Narrows with all the calving chunks with no problems, not to mention 800 miles of the Yukon River. With my previous experience with inflatables, I assumed they were all pretty good now days.

[Jimbo485]

Do you really NEED high performance? Why?

Shouldn´t the logical choice come down to practical, day-to-day application and use?

In our case, but maybe not yours´, we need a light, rowable, tough dinghy - three very important criteria. This means something that can be left on the rocks or a barnacle-encrusted jetty to smash away for a day without a problem; something that 2 people can lift and carry for 100 m across the mud flats when the tide goes out; something that won´t be blown away when the outboard dies because you can actually row it against a 20 knot breeze; something that can be flipped in the surf and then be recovered and rowed without outside assistance.

Straight away, for these reasons, inflatables are out. You still want an inflatable? Ok, get your handheld VHF, flares, etc ready, because you WILL need outside help at some point. In the Bahamas, I rescued 3 inflatables in just one day with our dink. No other inflatable dinghy even offered to help. To date, this is my record for daily rescues and I don´t think I will ever beat it unless we go back to the Bahamas, to RIB central.

If we were really into our image and were always in a hurry, we would probably think about SPEED and our APPEARANCE, especially "herself" standing up in the bow holding onto the painter, tits thrust forward, spine straight, while scooting across the bay at 15 knots. If we only cruise in the BVIs or the Whitsundays with mooring balls and/or dinghy docks everywhere, ok, we would go for a RIB. Maybe that is you. So go for it!

But what is left for OUR typical use of dinghies over the next few years?

Either aluminium (the infamous tinny), timber, plastic (PE/PP) or FG. In the end we went with plastic. Note that we really made an effort to find a decent tinny in the USA and actually drove 400 km in a hire car trying to find a decent one. Was just not possible. A jon-boat is not my idea of a tinny....

So we ended up with an ex-demo model WaterTender 9.4 (US$450 from West Marine) which has a tri-hull, is VERY stable, rows well and takes a good bashing on rocks, reefs and 3rd world wharves without a problem. Our other dinghy is a used WalkerBay 10 (US$700) which has the sailing gear, rows even better than the WaterTender, can be bashed about, but is NOT stable. Lots of fun though and easy to flip! So the WaterTender is our day-to-day dinghy.

We normally row one of the two. Why? Generally we are not in a hurry, since we try to plan ahead, and our distances to shore are fairly short - 0.8 m draft for the main boat means we are often close to the beach. Sometimes there is no need to drop a dinghy from the davits because we can wade or swim ashore. However, if the distance, the sheer number of passengers or the hurry-hurry-hurry context changes, ok, we put on the 3.5 HP outboard and scream away at 2 - 5 knots, sometimes even with the WaterTender towing the WalkerBay with the speed and grace of a thousand, thundering tortoises. We have motored the WaterTender for 6 miles each way in a 1 m chop, which takes time, care, additional fuel, etc. But if you are always in a hurry, WTF are you doing cruising? You might as well go back to the rat race that you are supposedly trying to escape from....

You want to increase the radius of your dinghy explorations? Well, just be patient, get really fit by rowing or change to a small draft boat so you can get in close, get up those rivers, etc. When we meet cruisers who have a dinghy with a 25 HP outboard and also express supposed pleasure at "getting away from the corporate rat race mentality" or "getting in tune with nature", we give each other a look, nod politely and wonder WTF they are on about with such hypocrisy. Obviously they still haven´t made the switch or are hampered by an umbilical cord attached to the Bahamas, BVIs, Whitsundays, their mother, their public image, their employer, whatever. This probably includes most of you, because most cruisers have inflatables with big outboards - ie. anything > 5 HP. Haha!! SORRY for being so direct!!!! Please enlighten us, not just on the practical aspects, but also the philosophical and mental ones.

If you only have a couple of months to cruise each year and you need to check your email at each port and your main boat has a draft of 2 m so you are usually anchored well out.... well, hey, get the RIB and the big outboard. You have got stuff to do and you need speed, baby!

But longterm it is easier to change the mental attitude, depart a few minutes earlier and still get there, instead of worrying about the rubber damage, UV damage, hurting your back with a big outboard, ferrying fuel back and forth, etc etc.

Or maybe it is us who are the crazy ones.....probably is, hey? Because majority and democracy rule, not logic and common sense?

[Katiusha]

Almost indestructible is a very good quality for a dinghy. I am a kayaker, so my other half and I had a lot of discussions about dinghy types. The conclusion was: if there is enough space for a kayak, we'll get it. But definitely it'll be a hard-bottom light dinghy with a nicely designed v-hull (our choice is Walker Bay Genesis, but to each their own).This way we can get back to the boat in a hurry should it be required. The hurry might be because another boat might be dragging its anchor onto us, the weather changes, etc. We also dive, so having a bigger radius of exploration while still being able to get back to the boat quickly is a big plus.

To each their own

[Therapy]

Good info here.
Thanks all.

[44'cruisingcat]

Originally Posted by Jimbo485

Do you really NEED high performance? Why?

You want to increase the radius of your dinghy explorations? Well, just be patient, get really fit by rowing or change to a small draft boat so you can get in close, get up those rivers, etc. When we meet cruisers who have a dinghy with a 25 HP outboard and also express supposed pleasure at "getting away from the corporate rat race mentality" or "getting in tune with nature", we give each other a look, nod politely and wonder WTF they are on about with such hypocrisy. Obviously they still haven´t made the switch or are hampered by an umbilical cord attached to the Bahamas, BVIs, Whitsundays, their mother, their public image, their employer, whatever. This probably includes most of you, because most cruisers have inflatables with big outboards - ie. anything > 5 HP. Haha!! SORRY for being so direct!!!! Please enlighten us, not just on the practical aspects, but also the philosophical and mental ones.

If you only have a couple of months to cruise each year and you need to check your email at each port and your main boat has a draft of 2 m so you are usually anchored well out.... well, hey, get the RIB and the big outboard. You have got stuff to do and you need speed, baby!

But longterm it is easier to change the mental attitude, depart a few minutes earlier and still get there, instead of worrying about the rubber damage, UV damage, hurting your back with a big outboard, ferrying fuel back and forth, etc etc.

Or maybe it is us who are the crazy ones.....probably is, hey? Because majority and democracy rule, not logic and common sense?

Depends on your use. If you're just going ashore, a little rowboat will do it (most of the time).

But we go waaaay up creeks and rivers fishing and crabbing. And there ARE time constraints - got to get in and back out on the high tide for instance.

We had one of the cheap Chinese thundercat copies. Was fun for a while, but basically started to fall apart from day 1. Now we have a 3.5 metre RIB with 18hp Tohatsu. It's great.

Only change I'm considering is changing the motor to a 4 stroke. Currently our tender uses more than twice as much fuel as our big boat! And if I fit a Honda 20, I'll have three of them. Talk about redundancy!

We also carry a couple of kayaks so we can do the rowboat thing too.

[downunder]

Cat man Do

Do you have any practical experience with either of the two duflex cat tenders you put up?

Actual weight of either? I am thinking to go that way. I note also Craig Schonning from Spirited Catamarans has another version and a couple of home builders of Schonnings have built their own.
http://www.admin.weblite.com.au/temp...ter%202011.pdf

[deckofficer]

My need is for a very efficient minimum wetted hulled "anything" that can ride the davits in all sea conditions. If there are hard boats out there that are light, have a tunnel or cat bottom, then I'm all ears, post the links please. Oh, I forgot the reason for this type of tender, it will be electric powered AND needs to have good range at planing speeds of around 17 kts.

[cat man do]

Originally Posted by downunder

Cat man Do
Do you have any practical experience with either of the two duflex cat tenders you put up?
Actual weight of either?

No

deckofficer
Oh, I forgot the reason for this type of tender, it will be electric powered AND needs to have good range at planing speeds of around 17 kts.

How heavy will those batteries be or will you just have a very long cord?