serene – 2, part 2

ntil this second design, I’ve been able to “read through” the hull designing parameters: Cp, Cb, Cm, Kmt, S, LCB, LCF, etc… interpret them correctly and know quite well what they do mean in real – world boat characteristics and performance. Many days out there paddling in various conditions and many hours spent on the whiteboard (a.k.a the Free!Ship software) make me feel very confident with my designing process.

The hull is shortened to 17 feet, reducing wetted surface area, but with minimum rockers, the waterline length is unchanged, also the designed – displacement is slightly increased to 120 kg, as 110 kg of maximum load is a bit under desire as pointed out in my last 9 days trip. Beam is slightly reduced from 45 cm to 44 cm, but both primary and secondary stabilities is significantly improved. I feel very pleased with this design so far!

Unlike my previous boat, the new one would have a curved deck. It is more difficult to build a round, curved deck, it is also harder to build hatches, compass cup, bungee cord anchor points and other parts… onto it. But with a curved deck, the boat will look nicer, less windage, and weigh less overall. Looking from above, it shapes exactly like a bullet, should I engrave a motto onto it: built like a gun, runs like a bullet !? 😀

The most important design decision is to increase the amount of deadrise. In my experiences with Serene – 1, the kayak has excellent sea – keeping abilities in rough conditions, something I didn’t feel with all my previous boats (e.g: the Hello World -3, which has a much flatter bottom). I would attribute that ability to the deeper V – hull, which offers quite a low primary stability, but should let you at ease in waves & turbulences.

serene – 2, part 1

‘ve been thinking a lot about the design of my next build. Serene – 1 is a good kayak, she has proved that during my last 9 days trip crossing all mouths of the Mekong river. The boat shows her excellent abilities in various conditions, big waves, strong winds and turbulences, even when overloaded a bit above her designed displacement, she gave me a kind of confidence that I’ve never felt with any of my previously – built boats.

In the quest for an ideal kayak that perfectly fits me, I proceed to designing my next boat, Serene – 2. Some lessons learnt from my last trip are immediately applied: first is a transom – mount rudder. I’ve been into conditions of strong wind blowing whole day, and without a rudder to help adjusting the bearing, corrective paddling would be extremely fatigue. This will have an influential effect to all other designing considerations.

LOA is reduced to 17 feet, approximately 3 times the height of my body. Since maneuverability is entrusted all to the rudder, the boat would have a very full waterline length, very little rockers at two ends. I decide to reduce prismatic coefficient – Cp further to around 0.5; my sustainable speed in reality (paddling at sea with full load) is only around [3 ~ 3.5] knot. There is no reason to waste energy for a higher speed that I can not sustain.

Block coefficient – Cb is reduced to 0.35, this would improve directional stability a lot. In Serene – 1, this value is 0.45, which explains the boat directional un – stability on long distance. Transverse metacentric height – Kmt increased to 21 ~ 22 cm, roughly equal to most popular Greenland sea kayaks, and hence greatly improve primary stability. With Serene – 1, this value is 17 cm, enough to frighten any novice paddlers.

serene – 1, part 30

mages below, 1st: the parts of the signal – light mast, 2nd: the signal – light mast (with the tubular radar reflector inside) in its erected position, 3rd: retracted position on the aft deck, 4th: the red – blinking signal light. I would install a small strap near the mast head to mount the GoPro camera. For the mast base joint on the deck, I was searching for a Rosette clamp (Vietnamese: ngàm hoa thị), so that the mast could be rotated around, but can’t find one, so I use this instead.

Last image below: the IC-M25 VHF radio used in conjunction with the radar reflector to avoid collision with big ships, it’s better to have a channel of communication with vessels around you and a way to ask for help when needed. The radio floats on water, it has about 11 hours of battery, and best of all, could be charged via a USB cable (that means it could be charged by a smart phone power bank). There’s another very important use of the radio: to listen to the broadcasted weather news.

I also hoist a tiny Vietnamese flag on the signal mast, not because I like hoisting color, but it’s good to gain some sympathy from the Vietnamese border guard or maritime police along my paddling way 😀. That’s about all I could do for my Serene – 1 kayak, preparing it for my next trip (that gonna be a long trip). Of course I have lots of other ideas on kayak building and equipments, but that would be reserved for my next boat, Serene – 2, which I’m gonna work on its design soon in the upcoming time.

Serene – 1 p1
Serene – 1 p2
Serene – 1 p3
Serene – 1 p4

The other day, I took Serene – 1 out to test paddling at full load, 16 bottle of water containing 1.5 liter each, so about 24 kg in total. Though the boat is a bit heavier to paddle, it becomes very stable at its nominal (designed) load. That made me feel very pleased and confident!

The boat could probably take a bit more, about 25 ~ 30 kg of load I guess. Since I designed it as a very lightweight sea kayak, I’m now having some headaches in loading it with appropriate food, drink and gears for my up coming trip (would tell about that in my next posts) 😀.

serene – 1, part 29

ext is the paddle float used to assist kayak reentry. Often we’ve seen experienced kayakers performing some kinds of rolling, but for most people, that could only be done with an empty boat. When it’s fully loaded for long journey, it’s almost impossible to roll that heavy hull. The most practical way is, of course, just climb in via the aft deck. My paddle float is just a supermarket plastic bag, I hate needle and thread things, but some little tailoring work would be needed to turn a bag into the float.

It’s just a quick job stuffing the bag with Polyurethane foam. The float is made such that it could be quickly attached (and detached) to one end of the paddle to assist boarding the kayak from water. One of the most important equipments for a cruising kayak is… a radar reflector. Here I should emphasize its importance a hundreds times, as with experiences gained in my previous paddling trips, your kayak is just so small compared to those huge freighters, looks like just a peanut shell in the sea.

And without a radar reflector, I’m sure that you would probably not be seen from above those high ship bridges. And as a big ship is approaching you, the situation is really critical: to be seen or to be sunk. Having a reflector would boost your boat’s radar signature, and it works best in combination with a marine handheld radio. My radar reflector would have a tubular form, erected on the aft deck, and it functions also as a signal light mast, with a red – blinking light attached to the top.

Serene – 1 p1
Serene – 1 p2
Serene – 1 p3
Serene – 1 p4

The elements of the radar reflector are made from thin steel plates, welded together to create some prism shapes. 8 pieces like that would be put inside a PVC tube (the signal light mast), which create an object with a radar – cross – section of about 1.4 m2 (estimated).

The ugly part about a home – made radar reflector is that you have no way to tell if this equipment works well, how big your boat would appear on those big freighters’ radar screens. But it’s better to have something, hoping that it should work, rather than having nothing at all.

serene – 1, part 28

am in the progress of preparing for my next trips… so some more add – ons for my Serene – 1 kayak is a must. First is a deck mount compass. I’ve been long wanting a good compass with built – in LED lighting, for paddling at night, but that would require some kind of 12 or 24 Volt DC electric input, which my kayak doesn’t have at the moment. So I came up with a simpler compass available within my local market, and would just use a small flashlight to illuminate the compass instead.

Next is building a “cup” to hold the compass, which would then be mounted, recessively, onto the front deck of my kayak. I use a thin strip of oak veneer to build the cup, turn it two rounds around the compass (with Titebond – 2 glue in between), then add the plywood top and bottom parts. The whole thing would be reinforced with some fillet at the jointing edges, then a layer of glass. It requires some handiness to build the “compass cup”, as its size is quite small and my hands are big and clumsy! 😀

I hate having to punch a hole into my kayak, but it need to be done to fit the compass holder in place. That’s quite straightforward the job, cutting a round hole some distance in front of the cockpit, just before the bungee lines, gluing the compass holder with some epoxy, then some little painting outside. Et voila, here it is, the compass in its working position, it looks so great! And as they usually say: May your anchor be tight, your cork be loose, your rum be spiced, and your compass be true! 😀

Serene – 1 p1
Serene – 1 p2
Serene – 1 p3
Serene – 1 p4

It’s not immediately obvious for me to see why this compass dial (the compass rose) is reversed, looking from above, it’s flipped so that the North becomes South, East becomes West. It took me some minutes to understand the rationale behind that “weird” fact 😀.

Cause in most cases, the boat handler would be sitting, looking forward, so the indicated direction facing him is actually the heading (bearing) of the boat’ stern (not the boat’s bow). Flipping the compass rose would give a correct and convenient reading for the sailor.

sectional kayak

ó ý tưởng này từ nhiều năm nay nhưng vẫn chưa thực hiện được… Giả sử như bạn muốn làm cái paddling trip nhiều ngày, đi thật xa, nhưng ko đủ quỹ thời gian cho chuyến quay về, hay đơn giản là muốn paddle loanh quanh suốt một ngày rồi quay về nhà nhanh chóng.

Thuê được một chiếc xe tải chở cái kayak dài 5.0 ~ 5.5m ko phải dể (dù cái kayak thực sự có chút xíu, rất nhẹ), và giá thuê cũng ko hề rẻ chút nào. Với cái thiết kế “tam khúc” này, có thể tháo rời thành 3 đoạn, mỗi đoạn khoảng 1.5 ~ 1.8m, và chất lên đằng sau chiếc taxi 7 chỗ dể dàng.

kim biên

hớ lại cả một quá trình dài 3 năm đóng & chơi 4 chiếc xuồng, hầu như tuần nào cũng lội chợ Kim Biên, chợ Dân Sinh… Đến cô bé bán hàng quen thuộc ở Kim Biên cũng lãi nhãi: Yêu a đi, tuy rằng a ko có nhiều tiền, đồ a xài mua ở chợ Kim Biên, nhưng cam kết là a có xe đạp riêng… yêu a đi a ko đòi quà… Nghe mà mĩm cười… 😀

serene – 1, part 27

inal entry of the Serene – 1 series. There wouldn’t be any major updates, add – ons for the kayak since most everything is completed, and I need to shift my times and efforts into some higher – priority tasks. In a sense, an important milestone has been reached, the designing, building and equipping of my newest beloved kayak. A fascinating process at the beginning of which, I didn’t even think I could make it, and I didn’t know where it would lead to, a nice useful watercraft, or… a disaster!

Serene – 1 is the best kayak of mine until now, outperforms all others in term of performance, lightweight and agile, pretty much fast, with some sacrifice in primary stability. Yet, it is not without some weak points that could be further improved, and that would be the concerns of my next boat project (still have no plan for that at the moment). I’d tried to get out with the best design, the best building as I could, learning lots of new things about a hull’s hydrostatics and hydrodynamics along the way.

But let me make a clear point about this, even the best cruising hull, the best equipments won’t improve your mileage by 15 ~ 20 percent, for a whole – day paddling. After all, it’s you, your horse – power output, your determination and physical endurance, which are the factors that could make a key difference. To be honest, sometimes, I have a strange self – satirising feeling that I’m quite like Popeye, the Sailor man cartoon character, especially before embarking on some longer journey! 😀

Serene – 1 p1
Serene – 1 p2
Serene – 1 p3
Serene – 1 p4

Where to go from here, now!? I have so many ideas on boat and boat – building, so much that I fear that I wouldn’t have enough time to carry them out all. But sometimes, I should be pleased with what I’m having, me, a nice little boat, and the immense water space to indulge myself in!

Time on water is the time well spent 😀, constant hard struggles, always keep a cautious eye on wave, wind and weather, be prepared for bad things, and reserve the other eye to enjoy the many different shades, different faces of the water. That’s truly serene for my mind then!

serene – 1, part 26

ontrary to my initial thinkings, the second Greenland paddle has proved to be the most satisfactory. Despite its short length (190 cm), I’ve found it the best balance between length, blades’ width, weight and force. And that’s explainable, cause I have small arms and quite a short arm span, in body building, could be called a “bottom – heavy” type, my upper part is not too strongly built, unlike the lower part. And that has some advantages as well as some disadvantages in kayak paddling.

I could often balance the boat better in shaking situations, compared to the “top – heavy” type, but also, I usually find myself understrength when prolonged heavy paddling is required. Overall, I’m very pleased with my new pair of Greenland paddles, especially the second one. And that’s an attractive appearance, my boat with the two paddles, all of one same nice wooden style! 😀 On my paddling route, I usually meet and have some talks with the captain of a 2000 – ton dry – cargo vessel named UT Glory.

He proposed buying my kayak, and before I could make a polite refusal, he insisted: you know, price is not the problem! 😀. Well, at least someone who really want to have a nice little boat like her that much! It takes some moments choosing the right words to answer him, that I won’t gonna sell her, Serene – 1, my self – designed, self – built boat! And for sure, he wouldn’t be able to find anyone who could produce just a simple, hand – crafted kayak in Vietnam though, as far as I know.

Serene – 1 p1
Serene – 1 p2
Serene – 1 p3
Serene – 1 p4

Apart from some plastic, fiberglass kayaks used for “tourist attraction”, kayaking as a real hobby in Vietnam is virtually non – existent. That explains why the kayak – building, kayak market in VN is virtually zero, though designing, building one is not any big thing, I would say. Why so!?

Frankly speaking, I think VNese is busy drinking and talking bullshit! Seriously speaking, I think VNese has salt in their mouths, but no salt in their blood! Truly speaking, I won’t hope they would do anything besides trying to cheat someone for some dirty purposes! That’s all facts!

serene – 1, part 25

aving gained some know – hows from my first Greenland paddle, I proceed to making the second one. This is not a “storm paddle” as mentioned in the previous post, but rather just an auxiliary, backup one. It would be shorter (190 cm), and wider (10.5 cm), as my first one, though suitable for long range paddling, lacks the force needed to compete against strong current and wind. I think it’s wiser to have a pair of paddles to compensate each other (and stop using the plastic one completely).

But first, I need to reshape my first paddle a bit, to make it even lighter, and turn the cross – sections from “rounded – rectangles” into real flat – ovals. The blades are still quite thick, especially at the edges, and they’re making quite some noises when entering the water. A good paddle should make as little sound as possible, so that the water birds wouldn’t fly away until you’d approached them within 4, 5 meters or so 😀. Well, those lovely water birds, an interesting story I would tell in another post.

5th image below: using a spokeshave to carve the edges (the rougher job is done with the machine planer already). I’d turned to love this tool, it removes wood easily and nicely. As I’m gaining more experiences with wood working, I feel more confident and rely more on the manual tools, as they allow me to do the finer jobs. 6th image: the pair of paddles, they’re just a little bit heavier than the plastic paddle, but feel like firm enough for hard uses though! Now ready for the glassing and painting tasks!

Serene – 1 p1
Serene – 1 p2
Serene – 1 p3
Serene – 1 p4

For true wild birds, it’s hard to approach them within 10 meters without signaling them on your presence. But for those “half – civilized” birds around my area 😀, they only fly away when I’m just 3, 4 meters apart. That implies some things on the city’s noise – pollution, I would suggest.

8th image: the blades’ tips get one layer of 6 – oz glassing on each side (which cover about 20 cm of blade length). Some light painting still needed to really finish them though, to protect the epoxy resin from UV! I’m eager to try out the two paddles in action in the next couples of day!