A trimaran daysailer for aging boomers



R2AK circa 2015:

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New member
I would like to see more! Don't even know what a Mongoose 25 is.
Hello Russell, The first, and currently only, Mongoose 25 was designed and built in St Croix by George ’Moose’ Silver (He says hello. I understand you worked together with proas in the 70’s). The first Mongoose 25 was launched in March of 2012.

I have family living in St Croix. They know I’ve been interested in building a open water capable trimaran for many years. The Mongoose 25 has been actively sailing around St Croix waters for 10 years without any major problems. The videos of her sailing around Buck Island at speed convinced me of it was a fun boat and fit my desired functions. Also, it appears to be a manageable sized project to build.

The boat is designed as an open water capable daysailer with a rotating wing mast, large cockpit, and open stern. I’m going with a retractable rudder in a cassette, a taller mast, possibly a fixed bow sprit as I’ll be sailing in the lower Chesapeake Bay. I’m hoping to build a Mike Waters carbon rig for the boat.

I’m not tech savvy enough to put the YouTube link in this post, but if you search for “Mongoose 25 Crankin” in the YouTube site a 6 minute video shows.

Please, let me know your thoughts about the boat.

Russell Brown

Super Anarchist
Port Townsend WA
I watched the video. It looks like a great boat. I remember Moose fondly, though I haven't been to St Croix since the early 80's, which seems like more than a lifetime ago.
Did Moose design the boat? Is there a complete design package?
The connectives and geometry look pretty simple and robust, but you must be a good builder to tackle such complex hull shapes. From the photos, the construction looks very clean.
I'm building a folding trimaran and just the ama's have been a large project, so I have an idea how much work it is.
Have you considered looking for a broken carbon mast to repair and use?
I have built a couple of rigs from Omohundro F-25 masts and would recommend buying a spar over building one. the weight savings and reliability could be worth it.


Super Anarchist
Sarasota - W. MA.
Getting back to the original premise - I can't help but be impressed by some of the "portable" catamarans starting to be around.
Some of these are clearly thought out - engineered.
I'm still not sold on inflatable, but foam filled hulls such as the X-Cat seem OK. Most importantly, I can tell by the construction and fittings that this was made by real engineers and marine pros - it's not a cheap attempt at portability:

Not cheap - but one thing about aging Boomers is that they may not be looking to save every dime. This is not a hiking boat but they sell small "chairs" called hiking seats for the AMA's.

As much as I am enjoying learning new things (sunfish style now), I can't help but think a MH was really the perfect boat for everything I did. If it wasn't for the size/weight and difficultly in FL Waters (docking, mooring), my Sprint was A-1 for most everything.

If there ever is a try-out for this type of boat here in Sarasota, I'd line up. Maybe the importer can be convinced to come down to our SSS Multi-Hull Regatta weekend - it would probably be worth his while.

I really like that tiny Astus unit also.....just a bit too small (only a 1 person boat)...but they have the right idea...I think it weights 75 lbs.

The various "aging booming" doing heavy mods to the WR-16 are, IMHO, creating one of the closest boats for a perfect Boomer situation.

If I was smart I'd get rid of all boats and do the $450 unlimited use yearly thing at SSS (Hobie, Sunfish, Small Sloops and fancier stuff - laser, even Flying Scot!)....BUT, the world is different when you don't own things. You'd think not - but not owning the boat means stuff like.....they can yell at you (management) and you can't take out for sunset sails. One thing about aging Boomers...we want what we want. I surely don't wish to have my boats back by 4PM...that's often when I start thinking about going out!

There is something liberating about knowing the vessel is yours...IMHO.


Super Anarchist
Benicia, CA
I think where you sail determines what you want out of a boat. You, in FL, don't care about getting wet while I really don't want a wet boat here in N. CA where the water never gets above 55. Similarly, winds here are predominantly wind-lee (no reaching) so I need/want a spinnaker and a boat that points. Finally, I sail in 2 kt current which means the boat has to be able to sail upwind against a 2 kt current or else have an outboard that will do so; and prefer 2+ kt to weather VMG in 6 kt winds or less (so quicker means more use out of it). And of course, the generic aging boomer must haves--ease of setup, ease of trailering, less strength needed (so smaller sails, lighter mast, lighter boat)... Cheap isn't a sine qua non, as you say. Just want to have a boat that is fun when I feel well enough to use it.
There is a Haines Tramp for sale in my neck of the woods, asking $2000 for boat on trailer with mast. A little bit of historical significance: I think this is Charles Chiodi from Multihulls Magazine, old tri, she still has all the lettering on it. Looks like it needs new tramps, running rigging and sails. Anybody have any idea what that would amount to in todays dollars?

Tramp trimaran.jpg


Super Anarchist
The belt
That's a lot of boat for 2 k. Beachcat sails, synthetic rigging, new tramps shouldn't cost too much.. Very good boat if structures and mechanisms are sound. A little slow but very comfy.


If you're a good scrounger it wouldn't cost much to get the sails, tramps and rigging. If you want new sails and trampolines, SLO has made them before.

It seems like a pretty good deal. I've seen people asking a lot more for Tramps that don't look as good.

That being said, most Tramps are now 40 years old. The adhesives they used to put them together haven't held up, so there could be a lot of work to get it in the water. I'd be more concerned about the time spent vs the money spent.