Tiki 21 Hatch design

[Roger]

After Pius's great trip around the Med, he raised the issue of hatch design. This started a discussion which we can continue here.

I have one-piece hatches that hinge outboard. They give great access when open and are completely watertight when closed. They are good for pretty much everything except sitting inside once there is water coming over the boat. Because I often sail offshore and have water coming over the boat, this has been a problem for me. I have racked my brains and made several sets of drawings of possible alternatives and have considered:

- Rory's design with sliding hatches and a canopy. Good for everything except easy access to the cabin - this is an issue for me as my family sail often on day trips.

- a permanent raised cabin (about 9") in the area of the standard opening with hatch access. This would be good in wet weather, and would allow me to sit up inside the cabin underway with the hatch closed. Still not great for general access to the hull.

- the standard Wharram design with a canopy/dodger to keep most of the water off the hatches. If the standard hatch can be made water-tight, I'm starting to drift in this direction.

What d'yall think?

Roger

[sailorjoy]

I have also one piece hatches. I want to change it into softhatches seen at "Sea People" No.4 from May 1985 page 18

Tiki 21 modifications by Maurice Killen. I think it could be watertight and easier to handle as one big hatch.

[Bill Proteau]

Hi Michael

Deciding which way to go is difficult. There are pros and cons for both.

Inside is much safer both from the weather and there is a lot more boat traffic than the outside so more immediate help if required. However the only winds are straight into you are directly behind you so on a big flood tide and SE gale you could do close to 100 miles in a day. The opposite could be true also which with my luck is what normally happens. Plus you are in a fiord so there are few beaches or coves to pull into for the night. Most of it is straight up and down. That means tying up to tree trucks and trying to stern anchor in deep water etc. It is also the long way to go. These passages are quite narrow so an oncoming wind will require a lot of tacking.

The outside is shorter but your on the real west coast with all its hazards. A SE gale would be perfect for blowing you up the coast but traveling behind the main outside islands is probably the best way. The channels are reasonably wide so you should be able to get a good tack in. You have lots of places to get out of weather also as there are lots of beaches protected from either NW or SE winds. 

All that being said your real problem as I see it is mostly tides. The channels inside or out have significant currents, 2 - 4 knots on standard tides let alone big ones. Combine these with a counter wind and the fetch that can build up is amazing. In Chatham Sound just outside of Rupert, when a 15 knot NW wind meets a strong Flood tide, a 4 to 6 ft steep chop builds up. Beating into this for hour after hour is not fun. At least you know the tide will change. When it does the conditions change just as suddenly.

If you go fully outside then you end up in Hecate strait. In Queen Charlotte Sound there is always a swell running but it is deep enough to mitigate some of the seas due to wind and current if you are far enough off shore. Not so in Hecate. Up by Porcher Island it is not deep at all and the current, wind and swell can build up into a truly frightening size. Hecate Strait is not somewhere you want to spend a lot of time in with a small boat.

My thinking is use the east side of the main outside islands as much as possible. Don't fight the tides. When the seas build up on the tide pull over and rest. I have gone backwards at full throttle in these conditions on my big boat. 

Hopefully this helps Michael. We will be in Rupert in June and drinking beer while talking about boats is a favorite pass time of mine. We look forward to seeing you guys. I really want to see how those petal drives work.

Cheers

Michael Dougherty said:

Great tips Bill - we're still trying to figure out whether to go full inside passage, sneak out into Hecate Strait, or split the difference by sneaking around the back of e.g. Banks Island. Any advice there?

I agree about the small sail area, I've fitted larger sails - a Hobie 18 mainsail at 176 sf (I've fitted reef points) and a modified Etchells 22 jib which is now about 90 sf, and it lighter airs it moves much better. Hasn't helped upwind performance as much as I'd like however. If we do anything with keels or daggerboards (I'm considering, but time is running out) I'll let you know.

For manual propulsion, see details I just posted in the separate thread.

Will you be in Prince Rupert in June? If we end up passing through there it would be fun to meet up. Let me know if you head to Seattle as well, there are a few Wharram fans here and we do like to drink beer and talk about boats!

Bill Proteau said:

Hi Michael. I was not aware of this race! I would love to go in this but I'm committed to finishing the refit on my big trimaran (www.pacificcloud.com) by Sept so can not afford to take that much time off.

We currently live in Prince Rupert which is just below Ketchikan (< 60 miles). I've taken my big boat through most of these waters and during the race time frame. You probably know all of what I'm about to write but if not then maybe it will help. June is a good month due to the way the tides work in the narrows. Large floods and minimal ebbs. There should be limited NW winds and maybe some SE gales to push you up.

Are you going to go on the outside or go up through the inside passages? Debris in the water is very high at that time of the year due to the spring run off so I would not travel at night. However it will be the longest days of the year and where we are the light lasts almost to 11pm and is up again just after 5am so certainly enough time to sail. What are you going to use for a second form of propulsion? I would worry about being caught in those big tide and no wind. I've played around with a sculling oar and it seems to work well but have yet to move beyond experimentation.

I'm following your other thread on keel stubs, daggerboards etc and in this area I would love to see what others think. The Tiki 21 is a good boat for this race due to its stability and all around practicality; carrying capability, beach ability, large sleeping platform etc but it does not point as well as I would like and has a small sail area. I know these are limitations due to design but I race my Tiki all winter long against monohulls and that extra 5, 10  degrees off the wind I must go and small sail size in light airs always loses me first place. A daggerboard or better keel is an area I am much interested in. In this race pointing will make a big difference especially if NW winds really pick up which they can. In the inside passage any outflow wind brought on by the NW will bring your progress to a complete halt.

Anyways I'm babbling as I love this race concept. I wish you guys all the best luck and tons of fun and if the suns align right maybe next year I can do it.

[Bo]

Did you ever try these soft hatches? I really liked the idea and wondered how it worked for folks. I'll attach a drawing from the magazine. 

sailorjoy said:

I have also one piece hatches. I want to change it into softhatches seen at "Sea People" No.4 from May 1985 page 18

Tiki 21 modifications by Maurice Killen. I think it could be watertight and easier to handle as one big hatch.

[Ian Bamsey]

I have the standard designed folding/sliding hatches on my Tiki 21. Before rebuilding the hatches I went through the design options and came back to the original design. I think the folding design is very good. Here are my findings on the standard design:

Under way: I can close up and avoid water coming in. I can quickly get in to retrieve food / kit etc. I can sit in the cockpit and fold the hatch to a half and slide this back and forward for shelter. Being able to do this quickly is key.

Alongside: the hatches are closed and keep the rain out. They fold in half and make a perfect dining table when sitting in the cockpit. When closed you can walk on them, which is very useful.

On the downside: The hinges are a bit difficult if you are not used to them. If I have significant water over the decks, water will force its way under the hatch lips and drip into the cockpit. I'm looking to improve the seals at the front to help this. My hatches are varnished ply. They take a lot of sun and weather, requiring maintenance. I've now glassed them. You need a way of securing the hatches. Green water or wind can dislodge a hatch. There seems no elegant way to secure the hatches, however, I use webbing straps with velcro and this works well.

I hope this helps.

Ian

[Ian Bamsey]

[Bo]

Thanks for the detailed reply and great pic. My hatches have deteriorated to the point that a rebuild is necessary so I am also considering other designs. Ian, did you consider a "soft" hatch during your search? In your hatches it looks like you omitted the triangular stiffeners mounted on the exterior athwartship - pluses or minuses for that?

Thanks!

Ian Bamsey said:

I have the standard designed folding/sliding hatches on my Tiki 21. Before rebuilding the hatches I went through the design options and came back to the original design. I think the folding design is very good. Here are my findings on the standard design:

Under way: I can close up and avoid water coming in. I can quickly get in to retrieve food / kit etc. I can sit in the cockpit and fold the hatch to a half and slide this back and forward for shelter. Being able to do this quickly is key.

Alongside: the hatches are closed and keep the rain out. They fold in half and make a perfect dining table when sitting in the cockpit. When closed you can walk on them, which is very useful.

On the downside: The hinges are a bit difficult if you are not used to them. If I have significant water over the decks, water will force its way under the hatch lips and drip into the cockpit. I'm looking to improve the seals at the front to help this. My hatches are varnished ply. They take a lot of sun and weather, requiring maintenance. I've now glassed them. You need a way of securing the hatches. Green water or wind can dislodge a hatch. There seems no elegant way to secure the hatches, however, I use webbing straps with velcro and this works well.

I hope this helps.

Ian

[Ian Bamsey]

Bo, Yes I did consider the soft hatch option, but on balance came back to the original design. I find I am in and out of the cockpits all the time. I think the soft option would take too long to clip back in place all the time. 

I did drop the triangular stiffeners. I used 6mm marine ply which is strong enough to walk on without concern. I don't find their weight a problem. I chopped up a nylon chopping board to make the hinge links. I have rubber tape stuck around the inside of the hatch to improve the seal. I have plastic strips on the inside of the front hatch to make it slide forward and back with ease.

Ian