Divers and Cats

[peter.bomberg]

I am looking (or right now dreaming) of getting a cat and living 3-6 months a year on it and the rest in the tropics, however in doing the analysis I seem to come up with more questions then answers, 50-75% of the time it will only be 2 people on the cat and max of 6 but we are creatures of comfort so I am looking at AC and dial freezers and so on, however the real issue is the dive gear.

Bye the time I add up all the weights I am looking at close to 1 ton of gear (the 2 K cylinders of 100% O2 and the 1K cylinder of Helium weigh in 500KG full and then the compressor and rebreathers and so on).

I am looking at ideally a 40-50 foot cat but am wondering will my additional load make it into a barge? (I would remove 1 head and 1 cabin completely and turn them into a dive room).

Any and all advice is welcome!

Ofcourse I would love to change to electric engines and batteries, but that is another story and another post (5 years out it might be doable if batteries get lighter)

[Little Otter]

It all depends on what type of cat you get, if you get a waterline cat ment for speed you would dangerousley overload it with all the gear, what you want is a good, heavy cruising cat that will take those kinds of loads such as a priviledge, or a prout.

[imagine2frolic]

Depends on your budget, and time schedule. If your budget, and time schedule are large enough. You can have exactly what you need by having it built. I am sure you have already found that everything is a compromise. It'snot hard toget what you want. It's just expensive.......BEST WISHES......i2f

[Captain Bill]

Peter, It kind of depends on what type of traveling in the tropics you intend to do. I'm a diver and a Cat owner. You are obviously a more technical diver than I am as I stick with standard open circuit equipment. I have an Endeavourcat Sailcat 44. Currently I dive off of it on the east coast of the US and the Bahamas. It's well built and carries a load well, but I'm not sure if an extra ton in one hull would work very well. The boat has a mechanical room which contains a variety of equipment. I currently keep 4 scuba tanks, a 5KW diesel generator, two persons dive bags and there is still plenty of room for a small compressor which I intend to add shortly. I would describe the boat as a liveaboard coastal cruiser. Though well built I think she's a bit top heavy for serious off shore work. My personal rule is I don't want to be so far off shore that I can't make shelter in 48 hours if the forecast turns to crap, but that's me.

She's very comfortable for living aboard (AC/heat, 7.5 Ft3 refrigerator freezer, drink fridge/Ice maker, Master cabin, Washer/Dryer, seperate showers, watermaker, water heater, etc). If you plan to cross the pacific, I might consider another boat, though a 30 ft sailcat has crossed from Panama to Australia.

The stern platforms work pretty well for diving, though the standard boarding ladders leave a little to be desired. I intend to add a real dive ladder to the starboard hull when I put in the compressor. There is a fresh water shower on the starboard hull and that makes it convenient for washing off gear. It might be well argued that the ladder should be on the port hull that way people washing themselves and equipment aren't in the way. That's something I need to consider.

In any case my wife and I love diving off of our cat. I'll be happy to address any specific questions you may have.

[Cheechako]

I bought a 42 ft cat prior to selling a 47 ft mono several years ago. The mono was down a good 5-6 inches on the water line (modern highly reputable cruising mono) We had raised the bottom paint and eliminated the boot stripe. We had the cat and Mono side by side at the dock when we took possession of the cat. We transferred the same gear from one boat to the other. The cat only went down less than 2 inches on the waterline.... more like 1.5". You may make your cat sluggish though, I never noticed it...

[peter.bomberg]

Thanks guys and my original plan was for a very fast cat so yes I looked and specked cats like the Schionning's and other that are capable of 20knt plus however my wife very quickly made it clear that no AC and a mini fridge and no freezer and so on where a NO go. And you know I actually agree with her as I realize the type of cruising will be 1-3 weeks passage and then a couple weeks at anchor or with very short passage as an example 1-3 months in Fiji and then move to the next island group.

I was actually thinking for a bit of skipping the tech diving as there is a lot to see and do at 130 feet (yes I can go to 210 on 21% O2 but the bottom time is sooo short) and with my rebreather I can easily go and stay down for a LONG time at 300 (good for clearing the anchor too)

I am looking at 40-50 feet ideally and only going to 50-60 if I need to due to weight, and so yes the Priviladge or Catalina are nice (but most likely out of my budget)

I agree with imagine2frolic however my budget is capped at 550K including all aspects (sails, cat, insurance, upgrades, etc...), also I do not believe in buying new (anything really) so I am thinking a 3-5 year old cat would be ideal and I am very impressed with the new nautitech 47 and with another 50-100K of upgrades/mods she will make a perfect dive and cruise platform I think, yes there are alternatives like the Salina 48 or the Privilege 495 but the real issue is will I make it too slugish by adding 800-1200 kgs of equipment, I can spread it out a bit as I am either going Open Circuit or Rebreather and they dont have to be collocated but it becomes more and more annoying if I need to spread out the rebreather related gases (and yes the idea of having 600 cubic feet of 3000psi pure 02 did make me think of a massive fireball (I have a plan for how to secure it but it means 700KG of weight in the rear of the cat!)

Okay I am rambling here, so what I am hearing is adding 1200Kg might not be such an issue?

[peter.bomberg]

Captain Bill, what compressor are you looking at?

[Randy]

You might talk to the actual designer or at least look at the cruising weight specs on the design you're looking at. In general with mutihulls light is right & the designer would know when you're crossing that line.
Good luck sounds like a great time.

[Captain Bill]

I was looking at the Nuvair 3E, but mostly because of its compatibility with my existing single phase 5KW 115V generator. I just don't see installing another diesel engine in my boat. There are others available if you have the generator power or don't mind adding another engine.

Compressors - High Pressure - Portable Models

[Jeannius]

With a budget of $550k you can get any number of 45-50ft cats including Privileges. An example on www.yachtworld.com is a 2001 Privilege 465 Easy Cruise at $499k. The 465 Easy Cruise is actually 49.5ft as the transoms are extended for load carrying and speed.

[Sunspot Baby]

Simplify. Breath air. Small compressor and 6 tanks.

George

[peter.bomberg]

Hi Sunspot, right now I am thinking you have a point, however as my passion is diving and the rebreather has many advantages but the biggest is silence (you can get right up to the animals as you don't sound like an explosion to them I would have a really hard time with giving that up).

I started (a while ago) and spreadsheet of items for the cat (spreadsheet with current, weight (need/nice/maybe) and so on, maybe I'll post it as a separate thread and have people add to it as I am sure I am missing tons) the aim was to 1 see the load and also the current draw to see if I could get away with going solar and regenerative ie no diesel and only have a tiny bit of gas for the dinghy. But as I said that is another topic, I will take Randy up on his suggestion and get the lightship and max load info from the manufacturers as I can not seem to find it for many of the cats, I also need polar curves as many don't have them available but the good news is the research and planning are fun

[skipmac]

Hi Peter,

From the comments you make about diving seems like you are doing some advanced, deep dives and the fact you want to take He along sounds like you want to do the dives safely. Stick with the mix for that kind of diving.

With a breather you should be able to get quite a number of dives from a few dive tanks so may be able to get by without taking a big He and O2 supply with you. Depending on the breather and dives should should be able to get 5-8 hours bottom time from a twin set of Al 80 cu ft tanks.

Depending on where you plan to cruise and how far from gas suppliers you will be, filling a few dive tanks for the trip should give you a lot of dives. If you take a compressor you can mix 10/70 for 300' dives and after a few dives top off the tanks with air to get something like 18/45 for 200' dives, etc. Using that technique and a breather you can get a lot of dives with just a few tanks.

[Randy]

You know I'd been thinking about diving in the tropics and sometimes like on the Great Barrier reef it seems like snorkling is all most as good as diving but then you get to wall dives the stuff just continues & before you know it you're deeper than you thought with the clarity.

Also the wreck sites in Truk & the Solomans are really fairly deep.

On a small multi I'd thought how to get a compressor set up. I gave up with knowing you've got to have a quality compressor & the weight issue.

[peter.bomberg]

Hi Skipmac, funny I did my calculations on very similar model, the issue I ran into was a cost question and a supply issue both He and O2 are really pricey in most of Asia and if I am in the outer islands in Fiji for 2+ months then I either pay a fortune (and head back to Nandi) or switch to OC.

I am willing to reduce the amount I carry with me if I have to but only once I realize how heavy my barge has become, lets face it if it's max speed is under 8knts it's painful to make any long passage but compromising and giving up on the 20+ I wanted (and realize I was being silly about)