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Hobie 33 Offshore Modifications

1. Babystay:

Set 7' in front of the mast, 5' behind forestay using the same size wire as the other rigging, with load carried belowdecks by a line to an ear epoxied into the hull at the forward v-berth bulkhead. Top of stay is set on the mast 4' above the spreaders, with an external halyard. Stops pumping of the mast in hard going and allows setting a staysail. It also allows jib changes without delay for hanking on, increases power in heavy air with a little jib overlapping the main, and improves jib-only balance in gale conditions by bringing the storm jib 5' aft.


Babystay and bagged storm jib on deck. Sprit and bobstay are also visible.


Babystay & halyard, set just above the spreaders.


The babystay anchor "ear", g-10 epoxied into the bottom, butting the v-berth area forward bulkhead, with a drilled hole for spectra cord tiedown. Design load of the order of 2000 lbs.

2. Bowsprit:

A sprit was installed. using two 6' pieces of 1 _ inch angle aluminum bolted to the toerail on either side of the bow to set sails 4' in front of the forestay. Sailing load capacity was increased by doubling the spinnaker halyard through a block at the sail head shackle, and stiffening the sprit by use of a bobstay. The increased luff tension, and reduced 55% midgirth greatly improved upwind performance with a double+ size 450 square foot headsail. With a 650 square foot asymmetrical reaching spinnaker heavy air planning was easy. The hull attach for the bobstay is a trailer-hitch U-bolt bedded in Bondo inside the bow to stop leaks.


Bowsprit and bobstay. Note crossmember forward of the pulpit tied into toerail.


Backside of the bobstay U-bolt in its Bondo bedding.

3. Sailomat 601 wind vane:

Wind powered self steering in heavy air eliminates both current drain and wet autopilot woes. Under development are adaptively shifting relative wind tracking angle with wind speed for surfing, downwind VMG improvement. Stock plastic air paddles were replaced with plywood; drag was reduced by replacing the thick aluminum airfoil oar with 1/4" G-10 fiberglass blade.


Self steering vane showing original aluminum oar.


G-10 oar at speed, showing no cavitation or drag.

4. Inboard style 12 gallon gas tank, 6 HP O/B:

The extra 10 pounds extends range from 120 miles to 320 miles in calm water till tanks-dry. Filler neck is short enough to stay below the hatch.


The 13 gallon gas tank, showing 3-axis strapping, filer neck (red), vent (white).

5. Battery under the companionway:

Moving one battery about 20 feet aft and adding a second one, combined with the added vane gear and fuel moves the boat's center of gravity about a foot aft, making it a world-class surfer when sailed short-handed.


Two batteries, red selector switch and distribution panel in sealable compartment.

6. Charging systems:

Offshore electrical woes are the rule, so three independent charging systems were installed, total weight 35 #: A 1 HP, 4 stroke weed wacker coupled to a 20 amp permanent magnet alternator; housed in a compartment built between the cockpit seats, abutting the companionway hatch; Four amps from four flexible solar panels; and a 10 amp propeller driven PM motor. The compartment blocks the low companionway hatch from flooding and reduces cockpit volume.


The weedwacker/alternator. This second-generation 10 lb lighter version is still under development.

7. Acrylic companionway door:

Acrylic allows visual check of vane gear from inside, quicker in/out access.

8. Rudder Overhaul:

The notorious Hobie rudder "system" was re-rivetted, a smooth shoulder machined on the top casting and a plastic thrust washers added to reduce turning friction for better light air windvane performance and reduced autopilot current draw.

9. HF radio:

A 100 watt Icom 706 mobile HF feeding a backstay-mast-bilge wire loop through an antenna tuner gave excellent results from 1.5 to 30 MHz . The radio was altered to cover HF marine and HF aeronautical as well as ham bands. Twice daily ham phone patches to home, weather information and even spinnaker trimming advice was obtained on the Bermuda trip.

10. Stowage/seat rest:

The seating in the Hobie lacks a comfortable backrest against the cabin sides, which was supplied by adding a one foot square by five foot long open front cabinet under the windows running along the settees. Also added were four squares of hull-side hanging pockets. Both additions gave dryer, more accessible stowage.


These under window lockers made a huge improvement in back comfort. Note the oversize windows, extra glassing between them, and stainless frames.


The smallest of four hanging stowage lockers made from netting hung on the hull.

11. LED cabin & running lights:

Electric consumption is another well known offshore problem area. Six cabin lights, a 2 mile masthead anti-collision light, and running lights total just over 1 Amp. The previous lighting drew 5 times as much.

12. Window beefup:

The sidewalls of the cabin between the windows, a well-known structural weak spot, were beefed up. Total window area was doubled to eliminate a tendency for seasickness when below. The plastic frames were replaced with stainless steel, and the stock lexan lenses replaced by clearer acrylic.


Heavy construction was necessary to double window size and strength.

13. VHF radio:

A masthead antenna was installed, with long lasting RG 142 teflon coax run inside the mast.. The range improvement was a help keeping in touch with the race fleet offshore, and reached the Bermuda 2 meter amateur radio repeater 70 miles out.

14. Real Head:

A one piece head with 5 gallon holding tank was installed with inlet and outlet thru-hulls. Offshore sailing with a porta-potti stinks.


The all-plastic head saved weight.


The thru-hulls & real indoor plumbing add complexity but make offshore life easy.

15. Chart table & support:

Another storm wave weak spot was eliminated with a 1 1/2 inch stainless pole set to support the broad aft part of the cabin roof. With the mast support pole a few feet forward, a navigation table and one burner stove were easily installed.


Aft cabin support, chart table. The Icom HF below was mounted to the underside of the table to keep it dry. Existing black mast support visible in front of surfboard.

16. Tiedown/stiffener rails:

Two parallel 6 foot 2x4 mahogany tie down rails were epoxied to the hull side by side, 3 feet apart between the companionway and the motor well to limit flexing of the flat aft bottom during surfing/pounding and provide tie downs for water bags, chain, anchors, and other heavy gear.


One of two mahogany 2 x 4 stiffeners laid against the hull. Note woven roving patches.

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